A mysterious kid from China who claims to be the rightful child of Mutsuki. She first appears in Happy Lesson Advance. She is very well versed in Kung Fu, and contends with Chitose at every chance possible. Despite that fact that she is first introduced wearing a red China dress, she prefers to dress like a boy. Not only that, but she apparently enough, is a huge fan of Hazuki Yazakura.

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.
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(Source: Anime News Network)

__Date of Birth:__ __Hometown:__ Urasoe, Okinawa, Japan  
__Date of Death:__ March 14, 2020

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!