Zetsurin!

Trama

Keisuke has always been plagued by a peculiar phenomenon: he frequently falls onto girls in compromising positions, leading to him being slapped. One day, a magical angel named Ririi and her fairy companion Chappi descend from the heavens. They reveal that Keisuke is a legendary hero and that his "accidents" are due to a dormant power in his groin. This power is the secret weapon needed to save the world from 100 demon lords who plan to destroy humankind. Upon this revelation, Keisuke feels an energy surge, and a large black gun barrel, the Zetsurin Buster, emerges from his crotch.