Teppei just transferred into Kaimei Academy, and he's pressured to join the Sket-dan by his classmate, Bossun. Then, one day, Teppei is attacked by a mysterious masked paint chucker, "Paint Mask"!
But to the one being 
bullied, it's dead serious!
¡Pero para quien es maltratado, 
es algo bastante serio!
¡Pero para quien es maltratado, 
es algo bastante serio!
Mas para o outro lado,
 a coisa é muito séria!