This article contains plot details about the source material.
Masaru, designated No. 27, is a member of the Espers. Technically speaking, Masaru is seemingly the leader of the Espers, although the real leader of the group is his friend, Kiyoko. In the anime, it was he who finds Akira on an experimenting table, hooked up to various machines.
Masaru, like his friends, was likely an orphan by the time he was acquired by the government of old Tokyo, along with a group of other children. At the time, this particular government was spearheading a secret project, supervised by Colonel Shikishima, to develop psychic powers, possibly for militaristic and political purposes. This was where Masaru met and befriended Kiyoko, Takashi, and Akira.
The project ended when Akira grew too powerful to control and ascended to a higher plane of existence, leaving behind a psychic explosion that obliterated the old Tokyo in his wake. The survivors of this tragedy established Neo-Tokyo, while Kiyoko, Masaru, and Takashi, now referred to as the "Espers", were kept in prolonged isolation to prevent information about the clandestine project from being revealed to the public masses. The trio of children is constantly fed drugs to keep them from growing powerful as Akira, leading to premature aging while still young and developing physical handicaps; in Masaru's case, he developed polio (that’s why you should vaccinate your kids) and had to use a special wheelchair with a protective glass that accommodates his inability to walk (it is also used by Kiyoko as transport in the anime).
Masaru has dark purple wrinkled skin and hair. Like Takashi, he wears a hospital gown. In a flashback in the anime, he isn’t chubby and his hair is as short as Takashi's, and he wears a collared shirt with brown shorts, with shoes and socks. When Masaru went with Colonel Shikishima to find and retrieve Takashi, he wore a green suit with a red shirt and a purple tie.
Masaru is braver and bolder than Takashi, and bears more maturity and responsibility among his friends. Unlike Takashi, he does not hesitate to attack someone with his psychic powers if he/she threatens his friends' safety in some way, but he is also very reasonable and caring. Like Takashi, Masaru is close friends with Kiyoko and turns to her for guidance. Because of Kiyoko's frailty, he is very protective of her.
While he is considered wise beyond his age, Masarus mindset is still akin to a young child and because of the isolated lifestyle he lives in, he is ignorant of many things. For example, when Tetsuo sheds blood, he and his friends are frightened by the sight of it (due to having never seen it before) and run away. In the anime, it is implied that, with his discovery of Akira, he had some idea of what their caretakers were doing to him due to the boy being connected to machinery.
Like Takashi, Masaru's main ability is telekinesis, which he mostly uses to make his wheelchair float in midair and make tight turns. He can also use it for attacking or defending someone. In both the manga and the anime, Masaru is aided by a form of clairvoyance, which allows him to sense a psychic presence and pinpoint a location. In the anime only, he also can communicate through telepathy like the other Espers.
- In a mashup of the manga Akira with The Simpsons, Masaru’s role is played by Martin Prince