Cannot Wait (待ってられない, Matterarenai) is an extra chapter included with Volume 21.
Summary[]
Charanko pretends to "exercise" while injured in the hospital to try and impress a nurse, but gives up when he notices that the nurse is blushing at Suiryu, who is hand walking with one hand. The nurse tries to stop Suiryu, but the martial artist claims that he disagrees, as he says that the heroes are fighting the Monster Association and that he has a new goal.