Shuuto 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!

Ratman was partially published in English, with the first four volumes published first by Tokyopop from May 11, 2010 to April 5, 2011, and later digitally by VIZ Media, under the VIZ Select imprint, from March 24 to June 23, 2015.