Boogiepop Missing: Peppermint no Majutsushi

ブギーポップ

Boogiepop (ブギーポップ, Bugīpoppu), also called the Eerie Bubble (不気味な泡, Bukimi na Awa), is the titular protagonist of the Boogiepop Series. He is the alter ego of Touka Miyashita. He is famous around the girls as the rumored Shinigami (死神, Shinigami), a creature who kills people when they are at their most beautiful point, before they can grow ugly and old. In reality, he is an Automatic Existence that awakens in order to eliminate Enemies of the World, individuals or being that threaten to destroy humanity.

Bio from Fandom, licensed CC BY-SA