|Saitou as he appears in OMEGA and OMEGA 2.|
|Gender||'Male' [genitalia; inorganic otherwise]|
|Occupation||Teacher [Physical Education]|
|Debut||Game of Lascivity OMEGA|
|Latest Appearance||Game of Lascivity OMEGA 2|
Saitou is a tall, muscular man, with short black hair that is buzzed on the sides. He has prominent teeth and very wide eyes, with a rough, commanding voice. He wears a white shirt with "Switch On!" written on the back, and red track pants with white stripes running down the outer seams. Most of his body is actually made of robotic parts; Manami Kinoshita notes that only his brain and genitals are still human, making him an android.
Saitou is energetic and dedicated to his job, enthusiastically breaking up a fight between Ayane Tendo and Sasa Ayanokouji and repeatedly taunting them while they are running laps as punishment, encouraging them to pick up the pace. He seems to frequently pick on Tendo in particular, likely because she is a troublemaker. Saitou can be seen in the background of OMEGA lifting weights in Mimi's classroom, and later is shown watering plants in the courtyard. He is also a viewer of Ai Koyanagi's webcam shows, as evidenced by the saved videos on his computer.
Notably, Saitou is apparently unaware that he is an android for the entirety of the first game, up through his first scene in the second game; upon realizing this, he malfunctions and enters a coma-like state. Manami overrides his personality and takes complete control of him at this point.
As mentioned above, Saitou is an android under the control of Manami; it is unknown why she is able to control him, though it is probable that she created him, as he is seen exclusively in her company for much of the OMEGA duology. Because much of his body is robotic, he is highly durable, able to endure damage that most humans would die from without so much as a scratch. His head is able to spin around, and his flesh appears to be removable without much effort. He can fly using thrusters in his feet, and is able to shoot off his arms for a projectile attack. The arms then return to him using thrusters in the palms, though using this attack removes the skin from his arms. He has a variety of modes, both for general purposes and sexual purposes, controlled by a watch that Manami wears.
Saitou makes his debut in OMEGA, as the University of Yomei's resident PE teacher. He is first seen breaking up the fight between Tendo and Sasa, assigning them laps and push-ups as punishment, and is later shown running the laps with them, encouraging them to outpace him. He is next seen in the science lab having sex with Manami, as Masaaki Ohara and Kayo Shinozaki watch, taking note of his robotic movements. He leaves before Manami, and is last seen briefly in the courtyard, watering plants.
in OMEGA 2
Saitou is a supporting character in OMEGA 2, in a larger role than the previous game. He first appears blocking Ohara, Tendo, and Sasa's path. Tendo attempts to fight him, but finds herself unable to do any damage to him. Finally, she hits him in the head, sending his head spinning around, coming to a rest backwards. When this is pointed out by the others, Saitou collapses in shock. Manami then reveals herself and changes Saitou's mode, taking complete control to continue the fight. Saitou is defeated when Tendo remembers Manami's dialogue in OMEGA and utilizes the Drunken Fist style, crushing Saitou's testicles.
He later appears on the roof for the climactic battle at the end of the game, along with Manami and Miyuki Kageyama. Manami sends him up to Chokugen to try and fight and save Mimi, but Saitou is easily knocked back to the roof by Chokugen. Saitou's last action is to catch Mimi after Chokugen drops her following Sasa's surprise attack.
- Saitou is the only inorganic character in the entire UMEMARO 3D canon, though his brain and genitalia remain organic.
- Saitou and Manami are the only characters to appear in both parts of the OMEGA duology to have an H-scene in the first game, but not the second. The opposite is true for every other recurring character.
- Saitou shares his voice actor with Daichi Maruyama and Hajime Tanaka.