Tetta Kisaki/Synopsis

History
As a child, dickhead was very close friends with Hinata Tachibana. They went to the same cram school together. Because of his high intelligence, Kisaki was always at the top in terms of grades and tests. As a result, the other children alienated him, which made him extremely isolated and lonely. However, Hinata was the only one who treated him as a human being. Kisaki was greatly moved by her kindness and gradually fell in love with her.

One day, as Kisaki was walking home, he saw Hinata being bullied. However, instead of going to help her, he was scared and hid behind a wall, watching the scene unfold. Suddenly, Takemichi enters the fray, engaging in combat with the bullies. Kisaki sees Hinata's expression during Takemichi's display of bravery and realizes that she has fallen in love with him. This creates a deep hatred for Takemichi, whom he believes has stolen away Hinata's favor.

Plot
Kisaki's name has been mentioned for the first time at the beginning of the manga, during a conversation between Takemichi and Naoto. The latter explains that Kisaki and Mikey should absolutely not meet each other in july 2005, because further to it, the Toman of 2017 would become an extremely violent gang and Hinata's death would occur.

After a time travel, Takemichi will divert Draken and Mikey's attention, avoiding Toman's leader and Kisaki's meeting. But despite everything, after the incident of the neighborhood party in August 3rd and the reunification of the Moebius and the Tokyo Manji Gang, Kisaki becomes the third division captain, substituting Pachin then in jail after the accident with the Moebius' leader, Osanai.

In 2017, the events are a bit blurry. We learned, thanks to Naoto, that Kisaki became the temporary leader of the Toman, instead of Mikey. Before that, he had take Draken's place, sentenced to death because of a murder he perpetrated.

Atsushi, Takemichi's childhood friend, is terrorized by Kisaki. That's by the way the reason why two times, he will commit suicide in 2017, too exhausted by the anxiety and the fear that the temporary gang's leader brought him. We then understand that as a leader, Kisaki is terribly intimidating. His way to act and to do things is so frightening that he unconsciously push his underlings to commit suicide.

Kisaki is also a cold blood killer. Whether by his own hands or by the interim of Kazutora or Draken, Kisaki has shown that he could be a murderer without equal.