- "O-O-Okay, have a good one, guys. I'm going off ahead now. Well then... Goodbye..."
- — Kubota, to the other players before entering Door 5
Teruaki Kubota (窪田 輝昭 Kubota Teruaki), known as the 9th Man by the other players, was one of the more elusive characters in Zero Escape: Nine Hours, Nine Persons, Nine Doors, as he became the first victim of the Nonary Game very early on. By entering Door 5 alone which he achieved by betraying the other players, he violated Zero's rules, hence activating the small bomb lying in his intestine and resulting in his gruesome death. His bracelet number is 9, although it could be theorized that his true value is actually 0.
Kubota had black frizzy hair which Junpei said resembled a bird's nest. His glasses were oval-shaped.
During the Nonary Game, he wore a pink undershirt with a beige and black waistcoat and a red necktie. The cuffs of his shirt were striped matching pink and white. He had forest-green pants to go with his purple and white socks that stand out from his black-brown combat boots. He wore the bracelet with the number 9 on his left hand.
In an old photograph that showed him as a scientist at Cradle Pharmaceutical, he wore a white lab coat over his usual attire and had slicked-back hair.
- "The most pitiful man in the story. There is nobody in this story you'd feel more sorry for than him. I mean, his body is cruelly blown to pieces from the get-go... So because of that no one will really find out much about him. So who was this man? Did he really die? All of the mysteries will be revealed at the end of the story."
- — Kotaro Uchikoshi 
When the Nonary Game began, Kubota was very quiet and reserved. Kubota was cowardly and Junpei remarked that Kubota "had only a fingertip's-worth of a grip on his sanity." He was initially quiet, not speaking at all until interrogated about his bracelet. He then remarked that he had a plan to escape and began ordering everyone around. Whenever he did talk, he had a nervous stutter and was fidgety. He also did not care about the other players as he said he wouldn't hesitate to kill Clover if she didn't cooperate.
He was apparently easy to manipulate and had trusted Gentarou Hongou, as seen by Hongou's confession of why he killed Kubota. This can also be seen in the fact that despite having prior knowledge of the previous Nonary Game, he thought that he would be able to go open and pass through the other numbered doors when he was only told that the conditions for deactivating the detonator had been altered.
Not much about Kubota's early life is known, other than that he was a member of Free the Soul.
During the First Nonary Game, Kubota was one of the four executives of Cradle Pharmaceutical and was Cradle Pharmaceutical R&D Supervisor. He was part of the creation of the Nonary Project, also known as the First Nonary Game. The First Nonary Game's purpose was to see whether humans could telepathically connect through the morphogenetic field. He created the necessary technology required for the Nonary Game. As the supervisor of the R&D department, he was the creator of the RED and DEAD devices used to open the numbered doors and conducted the actual experiments to test them. He also created the numbered bracelets worn by players in the First Nonary Game, since the bracelets were needed to open the numbered doors because of the concept of digital roots involved.
Nine Hours, Nine Persons, Nine Doors
Nine years after the events of the First Nonary Game, Kubota found himself kidnapped by a person wearing a gas mask and was forced to participate in the Nonary Game himself. While unconscious, he was forced to swallow a small bomb. He was presumably stuck in a room similar to the 3rd class cabin and escaped. Kubota soon met seven of his fellow players for the first time and ran towards the central staircase with Hazuki Kashiwabara (known as Lotus), Aoi Kurashiki (known as Santa), and Seven, but they happened to encounter Junpei. When he and Seven approached Junpei, Kubota said nothing and ran past him to two numbered doors. A few minutes later, Kubota and the other players were greeted by Zero via speaker and were explained the main purpose of the game and their time limit of nine hours.
While they were examining the central staircase, he revealed himself to Hongou, who went under the codename Ace later on. Hongou said that the DEAD only required one person to scan the bracelet and ordered him to investigate what was beyond Door 5, saying they would meet again later. However, it was really a trick to let Kubota unknowingly kill himself, since Hongou saw Kubota as a threat and his bracelet as a very potent weapon, because the number 9 had the ability to not change the digital root of a group when added. He also needed to keep him quiet because of his knowledge of the First Nonary Game, which would decrease the chances of Hongou's making it out alive. Kubota was also used to see whether the Nonary Game was what Hongou called "a poor attempt of a joke".
When approached by Clover to see what his number was, Kubota said that since they knew who 1-8 were and that he was the only one left, he showed his bracelet that displayed a 9. When Clover asked what his codename was, he told her he didn't need one since he had a plan. Clover soon asked him what his plan was and Kubota asked her whether she really wanted to know. She answered yes, and Kubota immediately held her by knife point and began ordering everyone around, saying that he wouldn't hesitate to kill Clover since all he needed was her bracelet. By this point, everyone had started calling him the 9th Man. After Kubota demanded that Hongou and Clover put their left hand on the RED, he proceeded to do the same and released Clover as he promised.
With a smirk, he said that he would see what was in Door 5, but before they could do anything to stop him, Door 5 had already closed. When Kubota tried to authenticate on the DEAD, he realized that Ace had lied to him. He started pounding on the door and begged the other eight players to get him out of there. When they were unable to, he took his last seconds to try to tell them that Hongou killed him. However, Hongou's identity was not revealed, due to Kubota's panicking, and he ultimately met his pitiful death. After Kubota's final scream and the sound of a loud bang, the players opened Door 5 to confirm his death.
- "In his mind's eye, Junpei saw the corpse again. The dark, reddish-black pool of blood... The scattered pieces of flesh... Organs strewn across the floor like the blossoming of a grotesque flower... The explosion that had torn through his body had been powerful. The 9th Man's neck had been twisted at an odd angle. Junpei suspected the detonation had thrown him against the wall. Half of his face was crushed, and the other half was covered in blood. Most of his abdomen had been emptied, either by the explosion, or by gravity. He had landed on his back, and stark white ribs jutted up out of his chest, like the legs of some sort of macabre crab."
- "What had once been a man's internal organs now looked like so much vomit... As though something had chewed up and spit out the better part of his torso. It was hideous, but worse still, it was cruel. It was hard to believe the thing on the floor had once been human... The black pool of thick blood... The lumps of glistening flesh spread across floor... The awkward, twisted tangle of shredded intestines... The head, wrenched to some grotesque, unnatural position... The man's glasses lay next to his head. The lenses were cracked, and the frame bent and distorted. And next to the glasses lay a bracelet, the number 9 still displayed on its face."
- "Chunks of torn flesh lay in an arc around the body. What remained of its intestines had slid out onto the floor. The pool of blood that framed it was half dry, but so thick that it had taken on a texture not unlike that of an egg yolk prepared sunny-side up. On the floor, next to the broken mass of the man's head, lay his glasses, cracks spidering across the lenses. The bloodstains near them had already dried, like scabs on the floor."
The eight players were horrified at the sight of his cadaver, especially Akane Kurashiki, who went under the codename June. Akane had became feverish and soon, she cried after wondering why Kubota had to die. The players felt pity for him and were angered at Zero.
After Light, who went under the codename Snake, finished reading the rules of the Nonary Game to the rest of the players, everyone started deciding on which door they would pick. Kubota's death was used as an excuse by Lotus and Santa to choose Door 4 instead.
Door 4 or 5?
Depending on the actions of the player, the player can choose which players are forced to enter beyond Door 5 and to the 1st class cabin.
- If Junpei enters Door 4, Hongou (Ace), Seven, Clover and Snake enter Door 5.
- If Junpei enters Door 5, Junpei, Seven and Snake enter Door 5.
The surviving players reunite
Later, at the large hospital room past Door 4 and Door 5, the players met up again and became happy at their reunion. Junpei figured that Kubota's death was the reason as they were happy that they were still alive, unlike Kubota, whom Junpei felt sorry for.
They soon noticed that the components of the RED for Door 3, Door 7 and Door 8 were missing so the eight players decided to split up and search the areas they can access. During that time, Hongou decided to go back to the 1st class cabin and went outside towards Kubota's remains. He successfully acquired the number 9 bracelet, which was right near Kubota's broken glasses. Hongou also found the knife that Kubota used to hold Clover at knifepoint, knowing that he might need it to escape.
Hongou quickly went back to the area he was supposed to patrol but encountered a drugged Nagisa Nijisaki, who was going towards the large hospital room. Hongou didn't recognize Nijisaki because of his prosopagnosia but did notice that Nijisaki was wearing Snake's clothes, so Hongou mistakenly recognized Nijisaki as Snake. When Nijisaki went towards Door 3, Hongou called out Light's codename, with no response from Nijisaki. Hongou thought that Snake was blind, so he either didn't recognize him or was conspiring with Zero. Thus, Hongou used Kubota's, Nijisaki's, and his own bracelet to form the digital root of 3 and to open the numbered door. Hongou quickly pushed Nijisaki inside Door 3, Nijisaki then wandering towards the shower room and soon meeting the same gory fate as Kubota.
In the library, Snake, who was trapped in the coffin of the chapel as part of the ploy of Nijisaki's murder, secretly told Junpei, as he didn't want Seven and Clover to find out, the truth about the First Nonary Game conducted by Cradle Pharmaceutical and its four executives, one of them being the deceased Kubota, who was in charge of the company's research and development division and developed the technology required for the experiment.
In the study, Kubota's identity was finally revealed in the photograph showing a scene of him and the other three Cradle Pharmaceutical executives commemorating the hopes of the Nonary Project succeeding in their favor. Although the four players had no recollection of meeting all four executives, Junpei felt that someone had secretly told him the identities of the executives already. Junpei soon realized that the body inside the shower room was Nijisaki (previously nicknamed Guy X or Mr. X by the players) and that three of the executives who were part of the creation of the First Nonary Game were murdered. Snake deduced that Zero's next target would be Hongou, since he was the head of the First Nonary Game, as it seemed that Zero's goal was to get revenge for the events that occurred 9 years ago.
At the incinerator past the study, the four of them met up with Santa, Akane, Hongou, and Lotus again. Junpei wondered where the gun Santa had used to force his group to enter the other Door 9, Hongou then revealing that he had the gun and used it to make Lotus his hostage. When Hongou tried to open Door q in the incinerator with his own bracelet, Lotus's, and Kubota's to form the digital root of 9 and open the numbered door, the RED did not authenticate, surprising Hongou. He tried multiple times to open the door and left his guard down, allowing Seven to attack Hongou. Junpei then revealed to the weakened Hongou how he had killed Kubota, Nijisaki, and Musashidou.
Virtue's Last Reward
In the Secret Archives of Zero Escape: Virtue's Last Reward, on the "Nonary Veterans" file, it mentions his appearance in the Second Nonary Game and his death in the game, as a skittish man who gets blown up.
9 is an unlucky number in Japan. 9 in Japanese is "ku" (苦) and can be translated as "pain, ill, suffering, agony, torture". As such, 9 holds a widespread superstition in Japan.
In the 999 Q&A, Uchikoshi says that if Kubota had had a codename, it would have been "Pigeon", which would also tie into his localized nickname "Bird's Nest". In kanji, "pigeon" would be the number 9 plus the kanji for "bird" (鳩
九 = nine
鳥 = bird
鳩 = pigeon
- "I-I-Isn't it obvious? There are nine people here. A-A-And you know who numbers 1 through 8 are. I'm th-the only one left." (to Clover, when she asks him for his bracelet number)
- "C-C-C-Code...n-name?" (to Clover, when she asks him his code name)
- "I-I-I-I-I d-don't need one."
- "B-B-B-Because I'm not going to stay here. ...With y-you."
- "Y-Y-Y-You sure you w-want to know?"
- "I-I-I-I'm going to do this!"
- "I-I-If you get any closer--!" I-I'll cut her open!"
- "D-Don't worry... I-I'm not going to do anything to her... If she just does what I t-tell her to, I'll let her go."
- "A-A-A-Are you an idiot?! W-W-What do you think?! I c-c-could slit her throat right now! I'll kill you if I have to. A-All I need is your bracelet."
- "Good... Good you're done. N-N-Next... You, right? You're the one with the number 1 bracelet right?" (to Ace)
- "Th-Th-Thank God you were all so c-cooperative! Now I can get out of this n-nightmare!"
- "Shit! Why isn't it stopping?! Goddammit! Y-Y-You l-lied! T-This wasn't supposed to happen! This is wrong! This is wrong! O-O-O-Open the door! Please! I'm begging you! Help me! Please, get me out of here! Get me out of here! A-Ah... Oh my God, oh my God, there's no time left...! Listen! I was lied to! He lied to me! He put me in here! It was him! He killed me! It was him! A...Aahh... Aaahhhh... Gyaaaaaaaaaaaaaaht--!" (before his death)
- The first syllable of Kubota (窪) is a Japanese homonym with one of the possible reading for nine (九), which can also be pronounced as 'ku' (e.g. 九月, read Kugatsu, meaning 'the 9th month' or 'September').
- While Akane wanted revenge, it is unknown if Akane intended for Kubota to die. Kubota did have a bomb in him, but this doesn't necessarily mean he was intended to die. Akane's fevers occur when she is closer to being incinerated in the past, and she has one after Kubota's death, implying his death goes against her mission. The Nonary Game was also apparently built in such a way that no one had to die and everyone could escape through Door 9. Akane weeps after Kubota dies, but it is unknown how much of her feelings are real. The ambiguity of this also adds to Akane's moral ambiguity.
- Complicating this possibility is the fact that Door q had been reprogrammed, which means that either Kubota would not have been able to pass through with Junpei and the others unless either Snake & Seven or Junpei & Clover stayed behind.
- The digital root of everyone's age (excluding Kubota): Ace (50) + Snake (24) + Santa (24) + Clover (18) + Junpei (21) + June (21) + Seven (45) + Lotus (40) = 243 = 2 + 4 + 3 = 9. Because of the symbolism, he may be 45 years old, as the digital root of 45 is also 9.
- The same theory could also have him being 36, 54, 63, or even 72.
- Kubota's hand is never seen pressing against the RED's scanner in the final version of the game. However, it does appear in the trailer, along with everyone else's hands.
- While Kubota is alive, the textbox that appears when he speaks always displays his name as "???", despite Junpei seemingly giving him the initial nickname of "bird's nest". By contrast, all the other players (with the exception of Lotus's opening lines), are identified by their initial nicknames (Lion, Prince, Silver, etc...) until the codenames are agreed upon. The Safe Ending flashback does, however, identify Kubota as "9th Man" when he speaks during that scene.
- In both the Japanese and American character ranking polls, Kubota is #9, which makes him the least popular character. This is coincidental with his bracelet number.
- Kubota is Kinu Nishimura's, the character's designer, favorite character.
- He is one of three characters to die regardless of the ending in 999, the other two being Nagisa Nijisaki and Kagechika Musashidou.
- Kubota enjoys progressive metal music.
- Uchikoshi once said that Kubota and Musashidou were lovers, albeit jokingly.
- In Zero Escape: The Nonary Games, his nervous sprite was modified so that he is looking to his left, likely so he makes more eye contact with Clover before he holds her at knifepoint.