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.

Every 60 years, the heavens conduct a sacred ritual called ETM12. This custom involves selecting worthy Eto-musume—celestial beings representing different animals—to become one of the members of the Chinese zodiac, or Eto-shin. However, since the first ETM12 two thousand years ago, the original batch of Eto-shin reigns with no one being able to replace them. […]

Even though they shared the same bus every morning and sat next to each other in class, Ayaka Kagari, the “Princess” of Tougetsu High School, was nothing more than an unreachable idol for Honoka Takamiya. The horde of students who worshipped the “Princess” was merely a nuisance to Honoka, living his lazy, regular high school […]

The story is from manga volume 23.