Kyosuke Shikijo is a promising star of the high school kempo club, and he is in love with Aiko Himeno, a transfer student and everyone's idol. When Aiko is taken hostage by bank robbers one day, out of desperation to save her, Kyosuke manages to sneak into the bank, but puts on a pair of knickers [PANTIES] in girls' changing room instead of a mask. In that instant, the perverted blood inside Kyosuke explodes and transforms him into Abnormal Superhero. He saves Aiko, and Abnormal Superhero is born. Kyosuke's sense of justice from his father, who was a detective and died in the line of duty, and the perverted blood from his mother, who was a sadomasochist, awakens his latent ability, transforming him into Abnormal Superhero with superhero power. Kyosuke is distressed by this and unable to confess to anyone, and to his favorite Aiko... The pair starts dating, each harboring secrets, then the most powerful enemy, Black Abnormal Superhero appears. Kyosuke is unable to transform in front of Aiko. It’s crunch time! Aiko is just about to be taken away, and Kyosuke....?!