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. Wait, is that Class-S hero Flashy Flash joining the fight?! Unfazed, the Monster Association continues ramping up its attacks, but its goal remains a mystery. Meanwhile, the martial arts tournament reaches the semifinals!.