Satoshi is the rookie teacher of the class that the Marui sisters are in: 6-3.
Usually referred to as Yabecchi (Yabe and Ecchi), Satoshi Yabe is the homeroom teacher of the Marui triplets and is often the source of many of the series' misunderstanding jokes. As a result, he is often called a pedophile, pervert and lolicon despite the fact that he is a good-natured teacher who always has his student's best interests at heart.
Yabecchi is a character in both Mitsudomoe anime series, Mitsudomoe and Mitsudomoe Zoryochu!, published by Aniplex with animation production by Bridge and the manga series Mitsudomoe, published by Akito Shoten and serialized in Weekly Shonen Champion. Yabecchi's original design is credited to manga writer and illustrator Norio Sakurai while his anime version is credited to Takaharu Okuma. Yabecchi makes his first manga appearance in volume 1 of the series and his first anime appearance in Mitsudome episode 1, "The Marui Family! The Good, the Bad and the Ugly!".