Nekomata: There is a handsome little brother living in my body. He is often jealous of a boy and a girl, and he is jealous of a boy when he is a girl.
Witcher: There is a beautiful little sister living in my body. She often gets jealous of a bunch of monsters because of me and packs them up and sends them back to her hometown.
PS: This is actually a derivative work, not original, but if you can find the original work, I will lose...╭(╯ε╰)╮
Concept: The idea grows on its own, resulting in the character being so OOC that my mother no longer recognizes it.