Sharing a set of official birthday greetings for Demon Slayer Zenitsu Zenitsu from Demon Slayer: Kimetsu no Yaiba to everyone.On September 3, a well-known Japanese animation company officially released a birthday greeting picture for my wife Zenitsu to celebrate her birthday.Zenitsu Gatsuma is a character in the Japanese manga Demon Slayer: Kimetsu no Yaiba and its derivative works.