Shibuya Goldfish Vol. 3 (manga)

Hajime and Alisa have good reason to be wary of the "Shibuya Sable," whose violent nature is legendary. Even so, when your world is overrun by man-eating goldfish, you can't afford to be choosy about your allies, and there's no denying the Sable is more than capable of holding his own. Better still, the Sable has a plan to take out the goldfish from within the city rather than hope for rescue! Joining up with the Sable means joining his cause, whatever the risks, but as the situation grows increasingly dire, it may be more dangerous not to team up...and bring the fight to the fish!