Nagisa is the younger sister of the Protagonist. She has presided over the household and does chores such as cooking and cleaning. She always cooks for him and makes lunchboxes for him.

Her feelings for her brother go past familial love; she has romantic feelings for him. She goes to drastic and violent lengths to "protect" her brother, because she believes that he'd abandon her if she didn't. Nagisa goes out to do "something important". Because of this, she's unable to prepare dinner