Happy lesson is about a boy called Chitose who was put in an orphanage when he was young, due to his parents death. When he grew older he took back his parents house and started to live there and attend high school. During high school he was often picked on but would usually fight his way out of trouble. This led to him failing his classes and at one point thinkng about leaving high school. His teachers all though that it was not his fault and that he needed a guardian to look after him.
So his teachers all decided to become his mothers and stay with him at his house. Chitose had no idea about this until he arrived home and saw his teachers appear one by one. He gradually accepted this and they all became a family.
The mothers are:
Mutsuki Ichimonji -
Teaches classic Japanese and homeroom teacher.
Kisaragi Ninomai -
The science teacher who loves inventing new things.
Yayoi Sanzenin -
The school nurse and also a priest.
Uzuki Shitenno -
The loveble art teacher who acts like a small child.
Satsuki Gokajo -
The tough pe teacher who loves competitions.
Chitose also has two adopted sisters from when he was at the orphanage. They stay not so far from Chitose and instantly the mothers have accepted them as there own daughers.
Minazuki Rokumatsuri -
The younger siser who loves Chitose and always wants to help him.
Hazuki Yazakura -
The eldest sister who is a famous pop star, Loves to eat food.
Chitose being a single boy has attracted a few grils who have fallen in love wih him, both of the girls who do not feel confident in acually telling Chitose. These two will try to do everything to get close to him, but then again he has no clue eitther.
Fumitsuki Nanakorobi -
The class president and has strong feelings for Chitose.
Kanna Togakushi -
Kisarghi`s childhood friend, also an inventor. Insantly falls in love Chitose when they first meet.