"The Capsules" was a non-canon name given to the teenage bōsōzoku gang that resided in Neo-Tokyo. Both founded and led by Shotaro Kaneda , The Capsules consisted of a loose group of friends including Kaneda himself, Tetsuo Shima, Yamagata, Kaisuke, Kuwata, Watanabe and Takeyama The Capsules have a deep rivalry with the Clowns biker gang.
The Capsules are involved in various criminal activities, including drug dealing, vandalism and, being a biker gang, reckless driving and endangerment.
All members of the gang are present in the film, but only Kaneda, Tetsuo, Yamagata, and Kaisuke are given significant dialogue. Kuwata, Watanabe, and Takeyama have voices but only talk for a small portion of the film.
We first meet Kaneda, Yamagata, and Tetsuo in and around their regular hangout. Later joined with Kaisuke, they quickly become embroiled in a battle against The Clowns and then took into custody after Tetsuo is taken by the military.
After being freed from military custody, the Capsules, as an organization, play little to no further role in the story of Akira. They appear in further scenes in school, and on nights out, but are heard to have largely disbanded at some point after Kaneda becomes involved with the Resistance later in the film[?].
We meet the Capsules, who are taken by their leader, Kaneda, to discover the site where a massive explosion annihilated Tokyo. Later, the Capsules realize they left Tetsuo behind, and they head off to find him, but not before scaring off their rival biker gang, the Clowns.