Kokoro Katsura (桂 心 Katsura Kokoro) is the sweet-natured younger sister of Kotonoha. Unlike her older sister, she's far more social and outgoing and worries greatly that Kotonoha has no social life. She has a good friend named Uzuki and affectionately looks up to Makoto as an older brother. Kokoro lives with Kotonoha, their mother Manami, and their father, Mr. Katsura. She is also a main character in the School Days OVA - Magical Heart Kokoro-chan. It was never stated what happened to her, or how she reacted, after the death of her sister in the bad endings where Kotonoha is murdered; however, in the manga, she finds her sister dead and calls Makoto in a panic. Also, in the aftermath of the ending Forever, Kokoro is shown to have left a drawing of her sister at her grave, blessing her to be happy in heaven, showing that her sister's death in any route brings great sadness to her and her mother.