The infamous Shounen Bat (Lil' Slugger) is terrorizing the residents of Musashino City. Flying around on his rollerblades and beating people down with a golden baseball bat, the assailant seems impossible to catch—much less understand. His first victim, the well-known yet timid character designer Tsukiko Sagi, is suspected of orchestrating the attacks. Believed only by her anthropomorphic pink stuffed animal, Maromi, Tsukiko is just one of Shounen Bat's many victims.