Okama

Okama is Japanese slang for homosexual or transvestite. Literally meaning "a pot, a kettle" this word, always with the honorific prefix "O-" refers to a gay man, especially one who is viewed as effeminate or a drag queen. Can be pejorative. The word originated in Edo period slang for the anus. In current use.

Trivia
In the story the two most prominent okama (Bon Clay and Iva-Sama) have the ability to change others(Iva) or themselves (Bon Clay) into either males or females.