What is oni chan?

Oni chan is a term used in Japanese to refer to an older brother. It is often used as an affectionate or playful way of addressing an older brother. However, in recent years, the term oni-chan has been popularized in anime and manga culture, and has taken on a more romantic or sexual connotation, often used by younger sisters to express their feelings for their older brothers. This has sparked controversy and debate around the potential normalization of incest in Japanese media.