HAPPY☆LESSON: ADVANCE(2003)

HAPPY☆LESSON: ADVANCE

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)