Manga by WAKUI Ken "Tokyo Revengers" Mangaka.
Not related to Tokyo Manji Revengers.
Ichigo Washio is a young man with a bright future—a bright future, that is, within the gangs of Shinjuku. When he meets Ringo Takamizawa, a fellow student hell-bent on revenge on those who took everything from his mother, the gregarious Ichigo doesn’t think twice about helping Ringo—even when it means it’ll pit Ichigo against men he’s looked up to his whole life. But Ichigo knows he’s in the right, and with his new friends and a healthy dose of stupidity to guide him, he’s ready to return justice to Shinjuku’s streets!