A girl who lives with Oshino Meme in an abandoned building. She loves donuts from the Mister Donut chain. At the beginning of Hitagi Crab, she was renamed "Shinobu" by Meme, who suggested that the name Shinobu (忍), comprised of a heart (心) under a blade (刃), matched her original persona.

She appears to be an eight year old girl, but was originally a beautiful vampire who had lived for more than 500 years. After the events of Koyomi Vamp, she was left in a weakened condition with no powers or traces of her original personality, and therefore had to abandon her "Kiss-Shot Acerola-Orion Heart-Under-Blade" name. Prior to being a vampire, she was a princess of unparalleled beauty. She was referred to as "Princess Beauty" or "Acerola" during this time, the latter being her original name. Eventually, she was turned into a vampire by Deathtopia Virtuoso Suicide-Master to save her from the curse of beauty.