Chitose's class president. Fumitsuki has a deep crush for Chitose, though he is oblivious to it. She has excellent marks and continuously tries to win Chitose's heart. At times she is very aggressive, seen punching people with great force in a comical manner in order to silence students B and C or to get back at Chitose.    Source - Wikipedia

Hitotose Chitose was always alone and untrusting of people but when 5 female teachers appear and started living together with him in his family's house as his mothers, things started to change and pick up, together with Hazuki-nee and Minazuki (his 2 sisters) everyday is a lesson.
 
(Source: Anime News Network)

Hitotose Chitose is now living together with his 5 teachers as his mothers when a mysterious girl appears and becomes their neighbor which turns out that that person is Nagatsuki Kuron who wants Mu-chan to be her mother so another sibling rivalry ensues as to who would end up as Mu-chan's child.
 
(Source: Anime News Network)

When Mitsuki learns that the highschool is going to destroy the old school building, she is saddened at the thought of so many memories being erased. Chitose and the rest of the moms spring into action to stop the demolition. During their efforts, Fumitsuki, Chitose, and Mitsuki finally realize their true feelings.
 
(Source: Anime News Network)

One guy. Five girls. One roof. It`s a recycled idea, but it never gets old. Happy Lesson is a kinetic take on an old genre. 
Chitose shares his house with five ladies. One might think the continued attention of this many girls would be a good thing, but too much attention can prove to be painful. Did I mention they`re also instructors at his school (hence the title)? Not only is he the subject of their abuse at home, but at school as well. Even when things finally calm down at night, all the rooms are taken so Chitose must sleep on the couch. 
(Source: AniDB)

An 18-year-old orphan named Susumu Arisaka returns to the town where he was born and raised only to discover that his five teachers have moved in with him to become his mothers!

Fumitsuki Nanakorobi