|Family and Relatives||Mr. Katsura (father)|
|Seiyuu||Megu Ashiro (credited as Aoi Kamizuki in the games)|
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 she worries greatly that Kotonoha has no social life.
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, to the death of her sister in the endings, however in the manga she found her sister dead and called Makoto while panicking with the fact that she can't save her sister. Also, in the aftermath of the ending Forever, Kokoro draws a picture to Kotonoha, blessing her to be happy in heaven, showing that her sister's death in any route brings great sadness to her and her mother.
As the younger sister of Kotonoha, Kokoro shares similarity with her like violet hair, fair skin and a pair of lovely eyes. Unlike her, Kokoro has two hair strands tied with beads (ribbons in Island Days) and her hair is only shoulder-length, similar to Hikari Koruda. Kokoro has short structure, being the second shortest characters save for Itaru.
Unlike her older sister, she's peppy talkative and full of curiosity. Despite being very young, her knowledge of intimacy far outclasses her older sister's and she feels sorry for Makoto when she learns he and Kotonoha aren't doing anything indecent. She can also be somewhat manipulative, such as threatening to lie to their father that Kotonoha and Makoto are doing something indecent to make him play with her or arranging for Makoto and Kotonoha to have sex in Summer/Shiny days.
The Visual NovelEdit
She serves only as a minor character and is generally seen with Kotonoha at heir home. She frequently teases Kotonoha about having a boyfriend and immediately demands to meet him.
Although her role is somewhat expanded she's still not connected to the main events nor does she do anything noteworthy.
Her role is greatly expanded in Summer Days, and futher still in Shiny Days. She can be in a relationship with Makoto.
Strip Battle DaysEdit
In her route is revealed that Kokoro, after several years of periodical raping by Makoto and unnamed protagonist of game, growed from cheerful child into silent and reserved girl. When protagonist threatens her that he rapes Kotonoha's daughter (which she has with Makoto in this continuity) if she won't obey him, Kokoro breaks completely and submissively leave protagonist to do whatever he wants with her.
- Her name Kokoro means "heart, mind and/or soul". In fact, the meaning was lampshaded by Kokoro herself in Shiny Days. Her magical girl identity also come from this meaning.
- Kokoro has 1 H-Scene in Summer Days but in Shiny Days she has a surprising 4 H-scenes.
- In the english version of Shiny Days, the sex scenes between Kokoro and Makoto were removed but otherwise the route for her good ending remained. Currently, the route to her two evil endings (Substitute and When the Asure Flew Down) remains inaccessible.
- Megu Ashiro also voices Youko Saionji and Kazuha Nijou.