Masaru, designated Number 27, is one of the three Espers, psychic children who are central to the events of Akira. He was likely an orphan acquired by the Japanese government as a child and became a test subject in a secret project overseen by Colonel Shikishima, aimed at developing psychic powers for potential military and political use. Along with Kiyoko and Takashi, Masaru was befriended by Akira, a fellow test subject whose uncontrollable powers eventually triggered the explosion that destroyed old Tokyo and sparked World War III. After that catastrophe, Masaru, Kiyoko, and Takashi were kept in prolonged isolation by the military, fed drugs to suppress their abilities and prevent them from growing as powerful as Akira. This regimen caused premature aging and physical handicaps: Masaru developed polio and requires a special wheelchair with a protective glass enclosure to move, often floating it via his own telekinesis.

Masaru’s personality is calm, reserved, and cooperative. He rarely questions the orders of Colonel Shikishima, showing a resigned acceptance of his captivity and role as a tool of the government. His primary motivation is to prevent another disaster like the one Akira caused, and he works alongside his fellow Espers and the Colonel to contain the threat posed by Tetsuo Shima after Tetsuo awakens similar psychic powers. In the story, Masaru and the other Espers act as a conscience and a warning force. They attempt to assassinate Tetsuo through psychic attacks, projecting themselves as giant toys to intimidate and harm him. Later, they help Shikishima locate Akira’s remains and, in the climax, summon Akira to absorb and neutralize Tetsuo’s mutated form. Afterward, Masaru and the other Espers use their combined psychic strength to rescue Kaneda from the singularity and disappear.

Masaru’s relationships are tightest with Kiyoko and Takashi, the only other survivors of the original project. They share a deep bond forged through shared trauma and isolation. He also has a complex connection to Akira, whose power and loss remain a constant shadow over his existence. In terms of development, Masaru does not undergo a personal arc or change his worldview; rather, he fulfills his predetermined role as a reluctant psychic weapon. His notable abilities include telekinesis, used primarily to levitate his wheelchair and defend himself, as well as a form of clairvoyance that allows him to sense the location of other psychics. He can also combine his powers with Takashi to create a construct akin to a giant toy car, enabling them to fight on more equal terms with a rampaging Tetsuo. Despite his frail body, Masaru’s psychic strength remains considerable and essential to the story’s resolution.