Tokyo Revengers Omnibus, Vol. 15-16

After all his work to change the course of history, Takemichi is confronted with the darkest future yet--a timeline where Mikey winds up murdering all his friends. Traveling back to the past, he finds the Tokyo Manji Gang in the midst of crisis. A massive rival gang from Yokohama is intruding on their turf, and their leader is none other than Kisaki Tetta! Time and time again, it's always been Kisaki standing against him. Takemichi starts to wonder: Could Kisaki also have the power to leap through time, just like him?