The female hero belongs to the Demon King.

A man summoned to another world as a hero. However, he found himself in the body of a woman. Following his calling, he defeated the Female Demon King and returned to his original world in his original body, only to find that the Demon King still exists there? Furthermore, upon returning to the other world, he discovers that the Demon King has something she didn't have before! ※ The hero alternates between male and female forms. Please refer to the [19+ Scene Classification by Episode] notice!