|Appearance||Period 6: Graduate Number 108|
|Fate||Deceased - Killed a year prior to the story|
Reiko was described as a girl who was noticeable due to her pretty looks. She had long, light-colored curled hair worn loose and big, feminine eyes. She was shown wearing a frilly summer dress in the flashback.
While she caught the attention of others Reiko preferred to be alone and kept to herself. She wasn't antisocial or rude, but she was mature and saw through Rina's fake personality, so she ignored her and didn't accept her friendship, leaving her friends to think of her as weird. She refused to suck up to someone to be accepted.
Reiko's ghost appears throughout the photo album Rina was looking through with her friends. After she goes to speak to her teacher about it, she sees Reiko's parents leaving his office. Her teacher confirms their identities to her and brings up how hard things have been for them with her having gone missing. It's been over a year but with graduation approaching, things had become even harder for them.
In this time, Miyu recalls Reiko, who had been a classmate of theirs and she begins to talk about her, saying that despite how pretty she was, she always ignored Rina's attempts at friendship. Rina says nothing other than telling her to stop and they return to class. By now the pictures are being more vibrant and seem to be moving, with her friends noticing one strange image that depicted the incinerator, followed by Reiko appearing on it, along with Rina. But by this point Rina grabs the album and runs outside.
Frantically Rina recalls what happened. Nobody could have taken this picture because nobody witnessed what she did. She approached Reiko the previous summer, once again offering to let her join the group. Reiko refused and bluntly told Rina how terrible she was, saying that she liked to be on her own and she didn't wish to suck up to Rina just for others to like her. She bullies people to be liked and everyone is too afraid to speak against her. Rina angrily grabbed her and shoves her to the ground, causing Reiko to be knocked unconscious after her head makes contact with a large rock. Rina then threw the body into the incinerator.
Rina mocks Reiko and claims she shouldn't have spoken down to her like that just because of her looks. However it doesn't matter now, and nobody will find out what she did if she throws away the proof. But before she can she is startled upon noticing the picture change again, seeing a charred spirit begins to rise from the incinerator. In a panic she throws the book in and attempts to flee until the angered spirit of Reiko rises and pulls her inside.
- She appears in her Academy uniform on the credits page of the chapter.
- It wasn't confirmed if she died from her head injury, or if she was knocked unconscious.