Happy Lesson is a manga series by Mutsumi Sasaki and illustrator Shinnosuke Mori, published in Dengeki G's Magazine from April 1999 to September 2002. It was adapted into two OVAs in 2001 and 2004 and an anime series from April 2002 to September 2003. The series is about five teachers who act as mother figures to take care of an orphan in order to make him into a good student.
Unsteady - Which Place is Big Brother's? (S01E04)
Satsuki gets a bloated belly when she loses an eating contest.