Shinobu Oshino (忍野 忍, Oshino Shinobu) is a mysterious vampire girl who acts as Meme Oshino's companion in the ruins of Eikou Cram School. Later in the series, she resides in Koyomi Araragi's shadow during the day.
She was formerly a human child princess named Rola (likely meant to be Laura in English) who was cursed into causing anyone in proximity to her to commit suicide. She then took the name of Acerola before meeting a purebred vampire that turned her into a powerful vampire named Kiss-Shot Acerola-Orion Heart-Under-Blade (キスショット・アセロラオリオン・ハートアンダーブレード, Kisushotto Aseroraorion Hātoandāburēdo). She now takes the form of an eight-year-old girl with another new name after losing most of her powers.

She is the titular protagonist of four main arcs: Shinobu Time, Shinobu Mail, Acerola Bon Appétit, and Shinobu Mastered, and four minor arcs: Shinobu House, Shinobu Science, Shinobu Figure, and Princess Beauty.