Ratman

Ratman is a ongoing manga by Sekihiko Inui and published by Kadokawa Shoten. The series has been licensed by Tokyopop.

Story
Shuto Katsuragi is a shrimp that can't catch a break. He wants to emulate his favorite super hero, Mr. Thunder, but instead he gets teased all the time for his height and he can't win any fights. The one thing that keeps him going is his love for super heroes, which he shares with his classmate Mirea Mizushima. Little does he know that she's about to make his dreams come true by tricking him into participating in her sister's experiments!