After being chased by her yandere boyfriend, Mitsuki Narita meets a stunning beauty. The girl was gentle and kind, and was her savior. Mitsuki Narita is determined to become a sister with her.
One day, my sister said, "Sister, I actually have a younger brother."
Social animal big sister x Help her with scheming
Demining:
The male protagonist is intersex
Intention: Two selfish people learn to love each other.