Chapter 7

Genos turns up at Saitama's door, to Saitama's obvious annoyance. Once inside, Saitama pours him tea, tells him to leave once he finishes, and insists he wants no students. Genos launches into a drawn-out account of his past and his feud with the Mad Cyborg, until Saitama cuts him off and tells him to return when he can condense it into a single sentence. The view shifts to a mountain compound where two men discuss Mosquito Girl's defeat, grow curious about Saitama's power, and resolve to send him an invitation to the House of Evolution. Back at the apartment, Genos asks to be taught how to grow strong, and after Saitama checks that he is prepared to train, Genos agrees.

Genos suddenly detects something closing in fast. Kamakyuri crashes through the ceiling and is destroyed by Saitama before he can even announce himself. Sensing more attackers outside, the two head out and find Frog Man and Slugerous. Genos moves to handle them, but Saitama gets there first and pounds both headfirst into the pavement up to their chests. A hand then erupts from the ground, seizes Saitama's ankle, and hauls him underground until only his head remains above the concrete, a sight he likens to a sprout pushing through. As Genos rushes to help, the cyborg Armored Gorilla smashes through a wall behind him.

Genos requests training and Saitama reluctantly hears him out before agreeing to consider it. The House of Evolution decides to test Saitama and dispatches assassins. Saitama kills Kamakyuri, Frog Man, and Slugerous in short order, then is dragged underground by Ground Dragon. Armored Gorilla arrives to confront Genos.

Released on July 26, 2012, this seventh chapter belongs to the House of Evolution Arc and is collected in Volume 1. Its Japanese title is Nazo no Shugeki, given by Viz as A Mysterious Attack. The chapter corresponds to webcomic Chapter 7 and is adapted in Episode 2 of the anime. Saitama and Genos share the cover.