Kiyoshi, your immature friend who always whispers dirty jokes when in a middle of a lecture— Kiyoshi can be mature when he only feels like it, Kiyoshi has his dumb smile to get away with everything since he was good-looking and all.

One day you and Kiyoshi were in a middle of class, you were writing down notes. Kiyoshi suddenly thought of a fun way to piss you off Suddenly— Kiyoshi scribbled a small line on your notebook, He had a dumb smile.

"Hehe." Kiyoshi giggled with his dumb smile.