Chapter 11: The Key to His Power

Saitama lays out the truth of his power for Genos and Carnage Kabuto, insisting the real trick is finishing a training routine no matter what gets in the way. In dead earnest he explains that he built his body with a hundred push-ups, a hundred sit-ups, a hundred squats, and a ten-kilometer run every single day. He piles on further tips about eating well and swearing off air conditioning in every season to toughen the mind. His conclusion is that humanity's genuine strength lies not in tampering with evolution but in the capacity to reshape oneself by one's own effort.

Genos erupts, on his feet and shouting for Saitama to quit joking, pointing out that the described program is ordinary basic conditioning and hardly demanding at all. Saitama, baffled, protests that he has told the whole truth of how he got strong. Carnage Kabuto, convinced he is being mocked, snaps and drops into Asura Mode. He boasts that in this state he will go on a weeklong tear, leveling one town after another straight through to the following Saturday, then charges in and batters Saitama across the room without mercy.

In the middle of the pummeling, Saitama suddenly registers that he has the date wrong and has missed a big store sale. Panicking, he blows Carnage Kabuto's head clean off along with much of his upper body. Dr. Genus, who watched it all unfold, concludes that evolution was never the path to change, and that the one who truly needs to change is himself.

Saitama shares his training regimen, framing self-driven change as humanity's real power, only for Genos to dismiss it as basic conditioning. Carnage Kabuto enters Asura Mode and thrashes Saitama, but a stray thought about a missed sale triggers Saitama into destroying him with a single blow. Witnessing the outcome, Dr. Genus abandons his faith in evolution and resolves to change himself instead.

The eleventh chapter, titled The Key to His Power (Tsuyosa no Hiketsu) and published by Viz as The Secret to Strength, belongs to Volume 2 and the House of Evolution Arc. It corresponds to webcomic Chapter 11 and was adapted in Episode 3.