HAPPY☆LESSON: ADVANCE

In the midst of a household where five female teachers live together with their student, Hitotose Chitose, a mysterious girl named Nagatsuki Kuron appears as their new neighbor. She reveals her desire to have Mu-chan as her mother, setting off a new sibling rivalry. As the household's dynamics shift, the teachers must navigate their relationships with Mu-chan and each other, all while facing the possibility of a new addition to their family.