Shuuto Katsuragi is a shrimp who simply cannot catch a break. He aspires to emulate his favorite superhero, Mr. Thunder, but instead, he is constantly teased for his height and fails to win any fights. The only thing that keeps him going is his passion for superheroes, a love he shares with his classmate Mirea Mizushima. Little does he realize that she is about to make his dreams come true by tricking him into participating in her sister's experiments!