Isuzu is a 15-year-old girl who lives close to Hiroshi. She is tomboyish and extremely affectionate towards Hiroshi, sometimes to his dismay. She had an older brother named Issei, who attended university before succumbing to his predatory instincts and attacking Hiroshi. He was killed by Nemuru. She herself starts to submit and attacks Hiroshi, but manages to stop herself and is spared her brother's fate.
Isuzu is a girl with short blonde hair with brown eyes and blonde bangs.
She wears a white and yellow shirt with brown trousers with black suspenders going down from her waist to her legs. she suprisingly has jingle bells attatched to her wrists.
She is kind hearted and energetic. She even tries to cuddle up with Hiroshi and hug him and even have fun with him.
Her personality changes after her brother's death to a sad and bitter character.