Life gets pretty boring when you can beat the snot out of any villain with just one punch. Nothing about Saitama passes the eyeball test when it comes to superheroes, from his lifeless expression to his bald head to his unimpressive physique. However, this average-looking guy has a not-so-average problem--he just can't seem to find an opponent strong enough to take on! Class-A heroes struggle in their fight against the giant monster Multieyed Octopus....

"The dangerous monster that can't be cut, Evil Mineral Water, confronts Bushi Drill, Okama Itachi, and Iaian. Meanwhile, Saitama runs into the giant demonic dog Pochi, and Terrible Tornado launches into an epic supernatural battle against Gyoro-Gyoro!"--

"Garo has just left the Monster Association's hideout when he crosses paths with Saitama, who's in quite a pickle, but Saitama still doesn't know Garo is the Hero Hunter. Later, King the Ripper can no longer hold back his murderous urges and confronts Garo himself"--Provided by publisher.

The Monster Association has kidnapped Tareo, the boy who admires Garo, and now Garo finds himself plunging headfirst and alone into the heart of the Monster Association's hideout. Meanwhile, the Hero Association pushes forward with its operation to rescue Waganma, while Genos and the others are living it up enjoying hot pot at Saitama's place!