Mikazuki Kiryuu  

, 桐生三日月

The girl is a classmate who is infatuated with Keita. They were both part of the same sports club at his previous school. Her behavior towards him is quite forward and she doesn't hesitate to show off her privates in front of others just to get his attention. She seems to be somewhat dimwitted, as she mistakenly believes that Miharu and Keita are no longer virgins after seeing them hugging. Yuuzukis is her older sister, whom she affectionately calls "my otaku sister" in private. Mikazuki looks up to her sister greatly and even bought a visual novel for her to enjoy. However, she also enjoys taking lewd pictures of her sister dressed up as a character from the series as a way of compensating for covering up for her. She was able to correctly deduce that her sister has feelings for Keita.