Takeshi has short blonde hair, pale skin and a rather large nose. He is cowardly and frequently hides from the monsters. He is unable to speak due to the immense fear he experiences (e.g. shivering, teeth chattering). In some versions, he will blame himself for bringing his three friends to the mansion in the first place, implying that it was he who initially suggested it. In the movie, instead of blonde, he has darker black hair in a different style. In the novel, he has rather a small and short height. He wears a white vest and black shirt in the second novel, he is also seen wearing a green sweatshirt. His pants are green cameos and he wears white shoes with black and yellow linings. His nose is smaller.
In Version 1, Takeshi meets up with Hiroshi and Kazuya along with Takuro, Megumi and Ryota. When they all got separated, Hiroshi finds Takeshi in a closet shaking. After Hiroshi finds Ryota's body, Takeshi disappears and is never to be seen again; meaning he escaped or was killed by the oni.
In Version 3, Takeshi is found in a closet at the start. He runs off shortly after, leaving the library key in the closet. Takeshi can be seen later in Hiroshi's dream with a cake stating that he planned the whole event. After the dream, Takeshi is seen with Takuro and Mika in the basement section of the mansion. He and everyone else flees after the oni enters the room and bites Takuro's head off. Takeshi and Mika lock themselves in a jail cell, while Hiroshi finds an exit. They agree to come with Hiroshi to the rope ladder exit. When they reach there, they see the oni consuming the ladder and flee, but Takeshi trips over and is killed by the oni, his head is left near the ladder.
In Version 5, Hiroshi finds Takeshi hiding in the upstairs closet very early in the game. He can be found later in a cave-like basement blaming himself for bringing everyone to the mansion and then runs off crying. He can be found in a random closet at the end of game. After Hiroshi saves everyone and the good ending is obtained, Takeshi has a nightmare. He is inside the mansion, being chased by the oni. He hides in a closet only to be found by an even more terrifying oni. He wakes up in bed soon after, panting and realizing it was merely a bad dream.
In Version 6, Hiroshi finds him hiding in a closet upstairs very early in the game. In his next appearance, Takeshi is found in a darkened room, and blames himself for bringing everyone to the mansion. He hangs himself, appearing later as an oni. It is not clear whether or not the monster possessed Takeshi and caused him to hang himself, using him to bait Hiroshi; or whether the monster attacked him after he had already hanged himself.
Takeshi is Takuro's lackey who has a big mouth and talks tough, but he's really as timid as a mouse. He's particularly cowardly when it comes to aliens and ghosts. Once he starts trembling, no force in the world can get Takeshi back to his senses. His parents run an eatery.
Takeshi is first seen with Takuro harassing Shun in the streets as seen by Anna who doesn't prevent anything we then see Takeshi waiting for Takuro with Mika outside the Jailhouse gates, when they all enter Takeshi stays with Shun in one of the halls until hearing growling sounds further down the hall. Takeshi decides to investigate Shun accidenlty knocks over a vase which startles Takeshi and makes him freak out and run around the jailhouse, he then hides in a closet staying there for a while. It isn't long before Mika and Hiroshi find him and try to convince him to come with them Mika grows angry with Takeshi and tells him that they will come back for him when they have found a way out, a few moments later Takeshi's phone goes off and he quickly answers it but no one answers leaving him upset. The door outside opens and he hears Takuro's voice calling for him a relieved Takeshi opens the closet doors but is grabbed by the face by the Oni, the others hear it and rush to the sound's source but the door is locked and they can't get in all they hear are the blood curdling screams of Takeshi and the sounds of him being torn apart. Hiroshi opens the door and the group find the tore clothes, the headphones and allot of blood and guts all over the floor.
- Takeshi's icon from version 3.0 - 5.2 is a running gag through out the entire Ao Oni series. This is probably because of his big nose in which the illistrator of the novel would put his famous icon face as bonus art. Many fans have portrayed him in art this way.
- In the fangame Heta Oni, Germany has Takeshi's big nose icon (until in the newer version his icon was fixed). Many mistaked Takeshi for Germany (Doitsu in japanese). Germany is a character from a very popular anime/manga series called Axis Powers Hetalia/Hetalia Beautiful World. This has been made into the popular fan made horror game/interactive novel Heta Oni.
- Germany also posses some of Takeshi's beginning actions fear moves in the beginning of Heta Oni for some reason.
- Another running gag is that when Takeshi is an oni, many fans would call him, "Germ-oni" because of the hair or how it looks.
- Takeshi also has the role of main antagonist of the South Park code.