Episode 2 - The Lone Cyborg

While Saitama waters his plants, the TV announces that the recent massive mosquito swarm is headed to City Z, where he lives.

He attempts to kill a mosquito but fails each time. In the abandoned city, a looter taking advantage of the situation has his blood drained by the mosquitoes, which are being controlled by Mosquito Girl.

She fights with Genos, who as a cyborg is not affected by the swarm, each taking a limb from the other. She then powers up by consuming the blood gathered by her swarm from the animals in the surrounding wilderness.

This causes the battle between her and Genos to become one-sided, but she is killed in one hit by Saitama. Genos appears at Saitama's door a week later asking to be his apprentice. He explains his situation in a long-winded monologue which frustrates Saitama.

Elsewhere, a man in a secret facility analyzes Mosquito Girl's defeat and decides to capture Saitama for his experiments. Back in Saitama's apartment, Saitama and Genos's conversation is interrupted by the House of Evolution's messenger, who is promptly destroyed.

Saitama is then trapped underground while Genos faces off against another cyborg, although Saitama soon escapes. He quickly defeats his two opponents and then questions the defeated cyborg, who panics when he realizes the rest of his team has been destroyed.

After the credits, Doctor Genus steps into a room full of worried subordinates discussing the fate of the team in City Z, when they turn around it is shown that they are all clones of him.