- "At any rate, this game ends now. I will escape, and the rest of you will have a slightly less pleasant ending. I suggest you enjoy your final moments. Goodbye."
- — Hongou, gloating his victory in the Second Nonary Game
Gentarou Hongou (本郷 源太郎 Hongō Gentarō), initially only known by his codename Ace, is one of the nine players abducted by Zero and forced to play the Nonary Game during the events of Nine Hours, Nine Persons, Nine Doors. He has bracelet 1, hence his codename Ace.
Ace is initially very altruistic, level-headed and nice to the players, but it is eventually revealed that this is a well-kept facade; Ace is in fact the main antagonist of the game, and was ultimately responsible for the event that resulted in its necessity. Despite this, he is actually not the mastermind behind the game's events.
Hongou is a tall man, being just under Seven's height and above Light's. He has visible abs in his main art but they are not visible anywhere else. He has gray-streaked brown hair worn in a manner that causes it to stand up and out. He has a chinstrap beard that is starting to gray like his hair. When Junpei sees Hongou, Junpei is reminded of a lion.
He wears a black, long-sleeve turtleneck shirt with pants of the same color. The shirt has a blue stripe running along both sides of it. A blue belt is tied around the pants. A knee-length lightly mint-green tones trench coat rests over his garments. He also wears black boots, which have a gray section on top. His trench coat was also used to store small items, such as a knife or bracelet. Like the other players, he wears a bracelet on his left wrist, but it tends to be hidden under his long sleeves and he pulls it up when he scans.
In November 2018, Hongou wore a white lab coat over a black-and-blue pinstripe outfit, a black shirt, a black fedora, and a blue tie. He wore black and white shoes. His hair was worn down and less gray. He also lacked facial hair. He carried around a cane for reasons unknown.
False altruism and deceit
- "Ace is the most dependable. He is always neutral about everything, and takes the lead as soon as he’s sure about what needs to be done. He is a gentleman. Kind, peaceful, but at the same time he has an aura of dignity about him that makes him popular among the other members. At one point, he risks his own life to try to save the others. I’m sure if you follow him, there will be no problems."
- — Kotaro Uchikoshi 
Hongou seems to trust the other players and advises everyone else to follow his lead, although he does things behind their backs. He claims he will not do Zero's bidding and will determine his own destiny, but ends up falling into Zero's trap mistakingly. Hongou has an altruistic outlook and acts very heroic at times to make the other players less suspicious of him. He is often the voice of calm reason when events descend into chaos.
Despite this, Hongou deceives the others, causing the death of Teruaki Kubota and a few others, since having his knowledge of the history of the Nonary Game would make him very suspicious. After he was discovered to be the culprit in the Safe and True Endings, Hongou becomes very cruel, sadistic, and uncompassionate about the other players and doesn't care about how many people he has to kill in order to escape. He also exhibits some psychopathic, sociopathic and psychotic behavior, and is the type of guy who would harm and kill an innocent child by incinerating her alive and laugh at her impending death.
Hongou is based on the "Achiever" Enneagram of Personality. Its vice/passion is deceit, much like how Hongou deceives the entire cast to benefit his own agenda.
- Main article: Prosopagnosia
Hongou suffers from prosopagnosia, which is the inability to recognize faces. It is never clarified how he acquired the condition, nor what type it is. However, it's implied that he both cannot "see" faces nor distinguish between them.
Instead of relying on faces to determine the differences between people, he relies heavily on visual cues such as skin color, height, clothing, and voice. He also uses bracelets to identify people, as shown in the Safe Ending. It's also possible that he doesn't use hair to recognize people, as he mistook Snake for Nagisa Nijisaki despite the two having very different hair which is a plot hole.
Hongou's prosopagnosia is taken advantage of on two occasions: when he confuses Nijisaki for Light due to their swapped clothing by Zero and when Junpei tricks Hongou into believing that he is Santa. However Ace is able to distinguish between the two because of their bracelets.
During some point of his life, Hongou became the CEO of Cradle Pharmaceutical, which was a failing business at the time.
Hongou was supposedly a devoted follower of a religious organization called Free the Soul, but actually only became a follower so they would be a source of funding for him. It is unknown when Hongou became affiliated with Free the Soul - it is possible this only occurred after Hongou played one of the original Nonary Games.
At some point in time, anywhere between 1980-2017, Hongou was kidnapped by the successor of Dashiell Gordain. He had became victorious in a Nonary Game and told Gordain's successor and his millionaire friends that he felt that if he could win the game, he could come up with a much superior version.
He, along with his fellow Cradle executives Nagisa Nijisaki, Teruaki Kubota, and Kagechika Musashidou, planned out the First Nonary Game in 2018. They were interested by Hongou's proposal and Gordain's successor sold him his ship where the Nonary Games took place, the Gigantic. Of course, Hongou's true intention was to test the theory of morphogenetic fields in hopes of curing his prosopagnosia, the idea of two organisms to be able to communicate with one another without any physical contact and through sheer force, and in addition to Musashidou's funding, the millionaires included their funding as well. Free the Soul also donated money towards the game, for some unknown intentions. Also, when Hongou investigated the ship, he discovered a mandrake root in All-ice's coffin, which was used to create the drug Soporil. As a result, Cradle Pharmaceutical's stocks increased drastically and some stockbrokers quickly took advantage of it. This included Crash Keys later on.
First Nonary Game
In order to start the experiment, he kidnapped 18 children for the experiment that passed a test at one of Cradle Pharmaceutical's hospitals. Kubota developed the technology needed for the experiment, with Musashidou providing the money needed to pay the costs and Nijisaki putting together the designs of the experiment. He categorized the 18 children into groups called the transmitters and the receivers. Depending on how well each child does on the test, he would put them into the sinking Gigantic if they were the receivers and Building Q in Nevada, a building with its interior built exactly that of the Gigantic, if they were the transmitters. Since he was the head of the Nonary Project, he knew the solution to every puzzle.
During the First Nonary Game, he was stationed at the Gigantic. His experiment had gone awry from the beginning, due to a couple of errors such as having a pair of siblings together in each building. The siblings together on the Gigantic were Aoi Kurashiki and Akane Kurashiki. Also, the detective Seven had interfered with the project by saving the four children who were left behind Door 9 located in the incinerator when five other children escaped through it. The four children left behind were Aoi, Akane, Nona Kashiwabara and Light Field. Hongou soon caught Seven rescuing them by pulling them up into a ventilation system although he manages to get Akane back when she went back to get her doll back. He went into the incinerator with her and near the RED, he put two numbered bracelets near it and quickly exited through the double-doors.
To test his only subject, Hongou told Akane that the two numbered bracelets he placed near the RED was numbered 1 and 3. Since Akane's bracelet number was 5, the digital root of those 3 numbers would add up to 9, allowing her to escape the ship. However, he had deactivated the verification function of the RED until Akane had managed to solve a Sudoku puzzle on a machine placed in the incinerator, which is going through automatic incineration. Although she was unable to solve it, her morphic resonance with Junpei activated and Junpei, who was placed in a similar situation as her, helped her solve it and let her and the others escape the Gigantic. Hongou somehow escaped the sinking ship, but it can be presumed he had escaped via the submarine in the storage room.
Later, he ensured that the public, media and the government did not know about the whole ordeal, and he and his company had the police and the media keep what had happened a secret.
Nine Hours, Nine Persons, Nine Doors
Nine years after the events of the First Nonary Game, Hongou was kidnapped by a person wearing a gas mask called Zero and was forced to participate in the Nonary Game himself. He was presumably stuck in a room similar to the 3rd class cabin and had escaped. Hongou was also given a note by Zero in his pocket:
- "Number 1.
There are 2 ways you might survive this ordeal.
The 1st is to win the Nonary Game.
The 2nd is for you to confess your sins of 9 years past.
I have prepared a camera in the captain's quarters.
The images captured by that camera will be streamed through a satellite and distributed across the world.
Simply look into the camera and repent.
Once you have confessed everything, I will release you from this ship.
To make your confession more credible, I have left you a witness in the captain's quarters.
Perhaps he will confess with you.
The decision is yours. Do as you please.
On the way down the central staircase, he had met seven other people before all of them had encountered Junpei. Along with everyone else, Hongou had ran past him to the two numbered doors. A few minutes later, Hongou and his fellow players were greeted by Zero via speaker and were explained what they had to do in the Nonary Game and their time limit of 9 hours.
While everyone was investigating the central staircase, Kubota revealed his identity to Hongou. Seeing as how Kubota was a potential threat to him because of his bracelet being of the number 9 and how he knew everything that had happened 9 years ago, Hongou tricked him by telling him to investigate what was in Door 5 by himself since Kubota now believed the DEAD inside only needed a single person to deactivate the bomb in his bracelet. Hongou also planned to have Kubota kill himself because he wanted to see if the Second Nonary Game was nothing but a joke. Later, when Hongou was asked what codename he would choose, he asked his fellow players to call him Ace.
Hongou's plan worked as Kubota took Clover hostage with a knife and as part of the plan, Hongou was forced to place his hand on the RED to open Door 5. Kubota entered Door 5 by himself and Hongou had managed to eliminate one of his biggest threats for him, with Kubota realizing that Hongou tricked him. Before dying, he tried to warn the other seven players who Ace was, but didn't mention his name in time.
After Kubota died, Hongou read the rules of the Nonary Game by Light, who went under the codename Snake, although Hongou had recognized Snake by his blindness and knew that Snake would be a threat to his survival.
If Junpei chooses Door 4
Hongou is grouped with Snake, Clover, a girl he didn't remember from the First Nonary Game since she was in Building Q, and Seven, whom Hongou didn't recognize as the detective who foiled Cradle Pharmaceutical's experiment, to enter Door 5 with, while the other players, Junpei, Aoi (Santa), Akane (June), and Lotus, entered Door 4.
If Junpei chooses Door 5
They soon noticed that the REDs of the three numbered doors, Doors 3, 7 and 8, had their main mechanisms missing so they tried looking for the missing pieces but to no avail. Hongou and his group soon reunited with Junpei and his group. As they exchanged information about the numbered doors they went through, Hongou and the others decided to separate to look for the missing RED components.
During his search, Hongou went back to Kubota's corpse (since Seven always goes through Door 5 and leaves a screwdriver in the exit of Door 5) and picked up his bracelet and also found the knife he used to threaten Clover with. Once he obtained the two items, Hongou pretended nothing had happened until he met the drugged Nijisaki wearing Snake's clothing at the large hospital room. Due to his prosopagnosia, Hongou assumed the man was Snake and decided to eliminate one potential threat to him, since Hongou remembered Snake from the First Nonary Game and also because Snake may have been conspiring with Zero. He quickly authenticated his bracelet along with Nijisaki's and Kubota's and pushed the drugged man into Door 3. He quickly left the scene and waited until one of the other players came back.
When everyone was done with their search, they discovered that someone had placed the missing part in each of the REDs, allowing them to function again. Junpei commented that Snake was missing and the players split up to search for him. Not finding him, they decided that they had to move on through the next set of doors. Lotus explained that the only way to allow the most players to proceed was to sacrifice someone and leave them behind. June opposed the idea but to allow the others to proceed, Hongou volunteered to stay behind because of his knowledge of what was behind Door 3. Hongou didn't want anyone to find the corpse in the shower room - if he stayed behind, there would only be two doors the rest of the players could go through: Doors 7 and 8, and it would be impossible to enter Door 3 (unless Junpei left one or two players behind, those being Santa or Lotus and Clover, which is a possible choice). Hongou injected himself with Soporil, knocking himself out, so that the other players could not take him with them.
The other players finally escaped from their rooms and surprisingly met back in the hospital room. The other players filled Hongou in on what they had discovered and decided to see what the keys that they had found could unlock. Clover stopped the group and explained that she wanted to check for her brother behind Door 3. Seven and grudgingly, Hongou, went with her to help. His group proceeded into the shower room but found the remains of a man whom they presumed to be Snake due to the man's clothes. Quickly escaping the room to get away from the horrible sight, they waited in the hospital room for the other players to get back. When they did, he informed them that they had found Snake dead and told them to look for themselves.
Afterwards, he suggested that the murderer must have been Zero himself and that the players must not allow themselves to be suspicious of one another. Clover states that Zero might be one of them. He comforted Clover by saying that Zero is manipulating her and calmly asked her to come with them to the Mercury elevators. There, Junpei suggested a voting system to see who was going into which door. Hongou picked Door 1 since he already knew the layout of the ship and wanted to go to the captain's quarters like Zero's note suggested to kill the "witness" with his knife, although Hongou didn't know who the "witness" (Kagechika Musashidou) was at the time. Clover also chose Door 1.
Safe / Zero Lost Ending
Hongou reluctantly went into Door 6 with Junpei, Santa and June, and he is worried about Clover, Seven and Lotus entering Door 1 and finding the "witness". While in the cargo room, Junpei asks Hongou to solve the face card puzzle, because of June suddenly collapsing near the electric fence. He rushes over to see if she is all right and leaves Ace to deal with the cards. June claims that she tripped and Junpei doesn't believe it, checking her temperature. Her fever appears to have struck again and Junpei suggests that they take her to a hospital after they escape. Santa mentions that Ace could help them obtain medicine and find a hospital, as he is the CEO of Cradle Pharmaceutical. When Junpei asks Santa how he'd know that, Santa claims that "Ace" told him earlier, which is a lie.
However, Hongou is unable to solve it due to his prosopagnosia. He tells Junpei that he is too tired to solve the puzzle and asks him to do it for him instead. At this point, Junpei suspects that Hongou has the disability that Lotus had told him about earlier in the laboratory. Soon after, a coffin is found containing a revolver with six bullets inside. He secretly pockets it, knowing he will need it to escape.
After they had escaped, they find two Door 9s in the chapel. While there, the group refuses to leave June behind because of Junpei's, Santa's, and Ace's bracelet numbers would make a digital root of 9. Junpei decides that they should go find the others and decide what to do next. Upon reaching the Central Staircase, they found out from Seven and Lotus that Clover had vanished. After hearing this all the remaining players search the ship for her.
Desperate to find her, as she knew information that could blow his cover since she went through Door 1 and probably found the "witness", Hongou tracked her down in the 1st class cabin. When she denied knowing anything, she tried to run away, but he caught up to her in the bathroom and killed her with Kubota's knife by stabbing her in the back. He then ran away from the room, still pretending to look for Clover, until Seven found her body.
Hongou pretended to be clueless on the circumstances of her death and waited while Junpei searched the room for clues. Junpei searches Clover's body and finds a note which lets him open a safe in the 1st class cabin. Inside the safe is a note that reveals Cradle Pharmaceutical CEO Gentarou Hongou was responsible for a Nonary Game 9 years ago. After a few minutes, Junpei requested that everyone go to the large hospital room, as he had found out who had killed Snake and Clover. Slightly worried, Hongou agreed and followed the group to the hospital room.
There, Junpei tricked him and causes him to reveal to the other players that he has prosopagnosia. Junpei continues, revealing to the group his evidence against him, such as tricking him into revealing he had the number 9 bracelet from the 9th Man, with Hongou providing a counterargument for each of his accusations. The argument between the two escalated until Hongou started to get angry, claiming that the paper Junpei had found in the safe was trying to frame him. Unfortunately for him, Hongou accidentally revealed to the others that he was Gentarou Hongou, the CEO of Cradle Pharmaceutical justifying that he knew of the events from 9 years ago. Junpei also revealed that he had found the 9th Man's bracelet in his jacket while he was knocked out. He responds by touching the pocket of his sweater. Junpei asked Seven to take it from him by force.
Hongou roared with laughter and confirmed that all of Junpei's accusations were true. He confessed to killing Nijisaki (known at that time as 'Guy X'), Clover, and, later on, encouraging the 9th Man to be killed. He showed no remorse for killing any of them, angering all the players especially Lotus. She punches him in the face but Hongou took out the golden revolver from the coffin in the cargo room and took Lotus hostage. He bid farewell to the rest of the players after his confession regarding the 9th Man's death and why he killed him and then made his way down to the chapel, but warned them that if they attempted to follow him, Lotus would die.
Upon reaching the chapel, he forced Lotus to authenticate at the small door 9 along with his and the 9th Man's bracelet. They escaped through the library and the study, en route to the incinerator. Just as soon as he was about to authenticate at the final door, Junpei, Seven, and Snake dashed into the incinerator. The incinerator turned on, activating in 9 minutes. Hongou made a fatal mistake when he taunted Snake about killing Clover. Outraged by this revelation and now determined to kill Hongou at all costs, Snake charged at him, who blasted Snake with a bullet from the revolver. This allowed Lotus to escape his grasp, but Hongou threatened the remaining three players, saying that he had enough bullets to finish them off if they refuse to hand Lotus back over to him. As Hongou was about to squeeze the trigger, Snake stood up, still determined to kill him. He stumbled over to Hongou, and Hongou used his remaining bullets on him. Not even this stopped him, as Snake's desire to avenge his sister's death pushed him to continue on.
Snake eventually got a hold on Hongou's leg, and realizing that Snake was going to take him down with him, Hongou pleaded for his life with an offer to treat his wounds at one of his Cradle Pharmaceutical hospitals. Snake declined his offer and told the other players to get out while they can. 10 seconds were left until incineration and Junpei tried to save Snake, but Seven stopped him by punching him in the stomach and dragged him out just in time. Hongou takes one last look outside of the incinerator before he was burned to death, saying to Zero that he didn't deserve his fate.
The result was that he, Junpei, and Clover would go into Door 1 and Santa, June, Seven, and Lotus would go to Door 6. His group found themselves in the chart room. He decided to search the wheelhouse, leaving Junpei and Clover to examine the chart room. After realizing that he needed the pocket watch to open the way for the Captain's quarters, he went back to ask Junpei for the pocket watch. He quickly went in the quarters and found a drugged Musashidou in the room. With an axe on the floor, he grabbed it and killed the man. He hurried back to the wheelhouse and told Junpei that he needed to check for something. Hongou slipped the pocket watch into his pocket, also taking the slips of voting paper out. As a cover-up, Hongou revealed that he knew all about Junpei's trick and how he had been able to manipulate the votes, but he didn't care since he was able to get through door 1.
The three popped the pocket watch in the exit door and found themselves in the communications office. There was a door with a "Captain's Quarters" plate on it and Junpei opened it. To everyone (except Hongou's) surprise, a man dressed up like a captain was laying on the ground, dead. Further examination revealed that the man was wearing a 0 bracelet and that he had been killed with an axe. He left Clover and Junpei to look through the quarters and searched the communications office. Needing Junpei's help to search the room, he went to retrieve him. The two found the Uranus key card and a mysterious file written in hieroglyphics. Junpei told him about what he knew about Ice-9 and All-Ice. Hongou suggested that if All-Ice was on the ship with them, she could have been the one who had killed Musashidou, as she would know all the secret passages around the ship. With no time to waste, they opened the exit and ran out.
They realized that they were back at the central staircase. Their group found the other players nearby and they revealed that they had found Door 9. Stuffing themselves in the Saturn elevator, they took it down to E Deck. Seven led the way to a small door. They rushed into the room and saw that it was a chapel. A big door 9 sat in the front of the room, with its smaller counterpart in the back. Thinking that everyone could escape now, the players rejoiced. Clover shattered their hope by calculating all of the possible combinations. It showed that if four people go, three stay behind and vice-versa. Seven suggested that they leave him behind, to everyone's protest. Santa interrupted them and quickly grabbed June and took a golden revolver out of his pocket that he found behind door 6. Santa decided to take Hongou and Lotus with him through the door and forced them to authenticate. After some hesitation (and persuasion from Junpei), they listened to him and Santa led them down to the incinerator.
Seeing his chance to strike, Hongou sucker-punched Santa and held Lotus hostage, dragging her to the final "door 9". Suddenly, the other four players, including a surprisingly alive Snake stormed into the incinerator. Hongou gloated about how he defeated Zero and authenticated with Lotus's and the 9th Man's bracelet after Junpei revealed that Hongou had prosopagnosia. To his dismay, it didn't work, no matter how many times he tried.
Seven charged at him, knocking him and the gun onto the floor. He gasped for air and Seven revealed that he was the detective that had helped the children escape back in 2018. Junpei revealed to the others that Hongou had killed three of the executives of Cradle Pharmaceutical: Kubota (9th Man) by tricking him into entering a numbered door by himself, Nijisaki by pushing him into Door 3, and Musashidou by swinging an axe at his chest. He realized that he had been manipulated by Zero to kill the executives, and that he had fallen for his trap. Junpei then asked Santa if he was Zero. He denied it, confirming that he was only an assistant to him. Santa explained why they had all been brought to play the Nonary Game, and after telling Junpei he had to save Akane, grabbed the revolver and pointed it at Hongou's head. He was dragged out by Santa.
After leaving the incinerator, Hongou was tied up, and tossed into the SUV trunk while Santa left with June. The other players soon escaped the facility and drove the SUV that Hongou was in. After asking him a couple of questions, Junpei sealed the tape back onto his mouth. While driving, Clover spotted a hitchhiker on the road, revealing herself to be an SOIS agent named Alice. She took them back to her headquarters and had Hongou arrested and incarcerated.
In regards to why Hongou wasn't killed by Akane in the True ending, Hongou was the person Akane felt the most animosity towards. Because there was so much hatred towards him, Akane didn't want to let him die that easily. She wanted him to admit his sins and either be judged legally or even just wanted him to admit his faults in public. This is Akane's and Aoi's motive: if the people involved all died, then the truth would have been lost. Akane and Aoi wanted everyone to know about the horrific event they'd been forced to take part in and who was behind it.
Virtue's Last Reward
He is briefly mentioned by Alice and Clover, as well as in the Secret Archives.
It is unknown if he survived the Radical-6 outbreak. Question 21 of the VLR Q and A said the third game would reveal what happened to him but it does not.
Zero Time Dilemma
He is briefly mentioned by Junpei in the Decontamination Room where Junpei thinks that he probably is currently still in jail, but is not sure whether or not that is true. Junpei also suggests the possibility that he escaped.
He is also symbolized by a lion on the slot machine in the Rec Room.
An Ace is the first value in a deck of playing cards.
The word "face" has "ace" in it, which may be intentional, referring to his prosopagnosia.
His Japanese alias Ichimiya is also pronounced Ichinomiya (一宮) which is a city in Japan. Literally translated, it means "the first shrine".
- 本 - can mean foundation/basis
- 郷 - can mean hometown/village
- 源 - can mean source/origin
- 太 - can mean senior; noble
- 郎 - can mean son
- "Hmph. You could never understand. You don't know what it's like to spend every day surrounded by monkeys." (to young Akane in the incinerator, after she asks him why he created the Nonary Game)
- "Then you'll die! You'll burn alive! Ah ha ha ha! It's going to be quite hot in there in a few minutes! I imagine it will be very painful!" (taunting Akane in the incinerator)
- "Good God..." (seeing the 9th Man's bloody corpse)
- "I trust you, each and every one of you. I believe you'll come back for me."
- "My goodness... I know I said I was sure you'd come back for me... I didn't think it would happen so soon, though."
- Ace: "There's nothing in the drawer."
Junpei: "Nuh-uh. There's air."
Ace: "How old are you?! 9?!"
- Junpei "Ace... You really kinda suck at making jokes..."
Ace: (sad face) "That was rather cruel..."
- "Very well. I admit that much. I am certainly the CEO of Cradle Pharmaceutical, Gentarou Hongou. So what if I am? I don't know anything about this Nonary Game that supposedly took place 9 years ago. Everything on that scrap of paper is bullshit. Someone is trying to set me up, you see!"
- "I admit it... I've lost. I have lost, completely and utterly. But don't misunderstand, Junpei. I didn't lose to you. I lost to Zero. Not you. I'm rather disgusted with myself for falling into such a simple trap. And it was a trap, make no mistake. I was trapped and manipulated by Zero."
- "Oh, it's quite true. I can assure you of that. I killed her myself, you see. I'm sorry, did I stutter? I killed her."
- "Why are you so upset that I killed the little bitch? She was nothing to you. A stranger you only met a few hours ago. Am I wrong?"
- "I would have rather she died with less suffering... A bullet in her brain, perhaps, would have been ideal. Unfortunately, that would have made quite a bit of noise. Circumstances being what they were, I was forced to settle for the knife. The one the 9th Man had, you remember? I believe I caught her just below the shoulder blade. I was rather lucky, in fact. My first thrust went right between her ribs. Her flesh was so soft. My knife slid in so easily... There was no resistance. That feeling was... I confess, I feel rather excited. It is a... powerful memory. Someday, perhaps, I hope I can feel it again."
- "I see. Then it would seem I have no choice. The rest of you must die as well. Fortunately, I have 5 bullets left. 1 for Junpei, another for Lotus, and the last 3 for that lump of idiotic man you call "Seven". I will take Lotus's body with me, and leave this room. Well, it looks as though our time together is at an end. I rather enjoyed playing with you. Goodbye."
- "Stay... stay away from me! Get back! L-Listen to me! I said, don't come any closer! Shit! You bastard! Y-You son of a bitch! You're... you're a monster! Get off of me! Let me go! Damn you!" (to Light, grabbing him in the incinerator)
- "Aaahh! Damnit! Damn you! Get off! Let me go, you monster! Okay, okay okay... Look. Think about it this way. My company owns a wonderful hospital. It has excellent doctors. Y-You're not wounded too seriously. I'm sure they can fix you up easily. You don't have to die. You can be saved! Just... let me go." (to Light)
- "Do you have any idea how much I've suffered? Can you even begin to understand my pain?"
- "I... I only wanted to see the faces. Human faces. I thought... I thought that if I could gain the ability to access the morphic fieldset, then perhaps I could see faces... By peering into people's minds, you could understand how they were processing the expressions of others."
- The artbook mentions: "The plan was for Lotus nine years ago to be having an affair with Ace." Whether or not this is still canon is unknown. It may be what Lotus refers to when she said, "I had them when I was young after... after some things happened." although the time of this affair may have been changed to about 20 years ago instead of 9 years ago.
- When June asked "Do you think Clover and Snake are really siblings?", and he answered "Why would you say that?", and Junpei says "They don't look alike", Hongou replied, "Now that you mention it". This foreshadows that Ace has prosopagnosia, as he can't recognize the difference between Snake and Clover, even though they look nothing alike. Another foreshadowing is found in the cargo room, when he refuses to take a look at his picture.
- Hongou is the murderer in the Submarine Ending. No one checked his pulse and he was pretending to be dead. Junpei also notes Lotus' bracelet is gone, a hint since Hongou would benefit the most from her bracelet (1 + 8 + 0). Also in the Submarine Ending, Hongou went through Door 1, which led to the Captain's Quarters where Kagechika Musashidou and the 0 bracelet were.
- He is also the one who killed Lotus and Junpei in the Knife Ending. Again, Lotus' missing bracelet is a hint to who was the murderer, as Ace would benefit from the "8" bracelet the most. This was also mentioned by Junpei when he saw Lotus' missing bracelet, although it wasn't established at that point that Ace had the "9" bracelet.
- In the Axe Ending, Hongou asks Lotus to come with him to discuss something. Although it is never revealed what it was for, it can be theorized that he planned to kill Lotus away from the other players to steal her bracelet, as he did in two other endings.
- Ace seems skilled in the art of murder. He is able to kill the 9th Man and Nagisa Nijisaki easily enough. Continuing this in the Submarine Ending, he kills Clover and Santa with a knife. He then manages to overpower both Seven and Lotus with a knife. Finally, he kills June and Junpei with a knife. It is also possible he killed Musashidou on this route since Ace went through Door 1. This means in total, he killed 8 or 9 people on this route.
- Additionally, Ace seems to be the most prolific murderer in the series; across all of 999's non-canon endings, he kills each of the other 8 participants at least once, and also kills his 3 co-conspirators in the true ending. Hongou is so skilled at killing that he unintentionally manages to kill himself in the Safe Ending.
- In the non-canon 999 novel, Ace dies similarly to the 9th Man at the end of the novel.
- He is familiar with the video game Donkey Kong, as seen in the steam engine room. He says, "Ah, yes, with the gorilla who threw barrels... And you tried to jump over the barrels, and make your way to the top..."
- In the character popularity polls, he ranked #7 in Japan and #8 in the United States.
- Hongou was referenced in AI: The Somnium Files, a Spike Chunsoft's 2019 game by Kotaro Uchikoshi. If the player chooses to read the autograph on the left in Mayumi's Somnium, Aiba will read Hongou's autograph. After Date asks her who he is, Aiba replies that she doesn't know, as she can't picture his face, referencing Hongou's prosopagnosia. After this, Seek a Way Out's theme plays for a brief moment.