This article contains plot details about the source material.
Yamagata (山形) is a former member of Shotaro Kaneda's biker gang. As it appears to be in the manga, he is of a higher position in the gang than most members, being closer to Kaneda than most gang members.
Yamagata is very tall for his age, standing at 188 cm (or 6'2,). His outfit varies in the manga, going from a dark jumpsuit, to a simple jacket T shirt and jeans, but he does not wear his most commonly depicted outfit until towards the end of volume 1, which is a red undershirt with a collar, and a grey over shirt depicting a symbol of the Rising Sun Flag with an image of a mountain. This is the outfit he is shown wearing in the anime, with some slight differences.
Yamagata is shown to be rather brash and rude, having little consideration for others besides his friends. It is also somewhat implied in the manga that Yamagata is unintelligent, having trouble pronouncing large words.
Not much is known about Yamagata's early life except that he is a member of Kaneda's biker gang. It could be speculated that he is an orphan along with Tetsuo and Kaneda.
He is good friends with Kaneda, Kaisuke, and formerly Tetsuo. He mostly tags along with Kaneda in the manga, until Kaneda is briefly separated from the gang, getting involved with the rebellion brewing inside Neo Tokyo. Before this, Yamagata was mostly involved in fights with the Clown Gang, an enemy gang to Kaneda's. Kaneda later comes back to the gang to formulate a plan to kill Tetsuo, who at this time had obtained psychic powers and went rogue and took over the Clown Gang. This attack is mostly led by Yamagata, who corners Tetsuo with the help of other bikers and separate bike gangs.
Tetsuo is then confronted by Kaneda, who hesitates to shoot Tetsuo despite Yamagata's encouragements. During the scuffle, Yamagata picks up Kaneda's gun and tries to shoot Tetsuo himself. However, Tetsuo ruptures Yamagata's body with his mind, killing him.
- Yamagata appears in only Volume 1 for the most part, only reappearing at the very end of the manga as a ghost riding next to Kaneda.
- Yamagata has no known last name.