Saitama and Genos glean information about The House of Evolution and its founder Dr. Genus, a scientist with dangerous ideas on artificial human evolution. Meanwhile, Dr. Genus learns of Saitama’s amazing strength and has plans of his own for One-Punch Man.

As the battle with the Deep Sea King reaches its climax, more heroes fall to the aquatic despot’s brutal attacks. Which of them has what it takes to be a true hero?