Yamaguchi Yu worked as an undercover police officer in Brahma, Tokyo's largest criminal organization. At the same time, in order to find out the cause of his sister's death, he was discovered and shot by Kisaki and others. When he woke up again, he found that he was reborn in the first year of high school. It was still 2 years before his sister's death. In order to find out the relationship between his sister and this organization, Yamaguchi Yu approached the Haitani brothers and successfully joined the Kanto Manhui, the predecessor of Brahma. With the complicated interest relationships within the organization and the constant struggles between groups, can the relationship between the sister and Brahma be discovered this time and prevent the tragedy from happening again?
About the world line: Create your own world line. The setting is that Kurokawa and Kisaki successfully established Tokyo Mankai with Mikey.
Intention: Self-effort and change destiny against the will of nature