A teenage girl who is a fan of Kouga's. In the manga, she had a history of prostitution. She and many other women were invited to a "party hosted by Kouga," but created by Jirou Nakata as a way of bringing Kouga to his side. Manga spoiler

Spoiler

During the party, all the other girls were killed, but before she could be killed by the Kouga clones, she was rescued by Ichirou, who couldn't stand by and let his father kill any more innocent people. While trying to escape with Kouga, she was shot by Jirou, though survived due to a makeshift bulletproof vest created by Kouga. After they escaped, her memory of the incident was erased by Amagi Corp.. Two years after the event, she and Kouga are dating, though she considers herself unworthy of him, due to her past of prostitution. When she was on a Christmas Eve date with Kouga, she tried to have sex with him. However, Kouga's memories of the incident with Jirou prevented him from doing so, devastating Mayu.