Mayu's first and only crush since kindergarten. After rejecting her on the day of elementary school graduation, he appears somewhat indifferent to her, though at one point does give her the "okay" to romantically pursue him. He is noted for turning down the popular girl in school, Kanemoto, when she asked him if he would like to go out with her. He also claims that he won't date someone he doesn't know well. He dislikes sweets. Shinya had a crush on Konoha when he was younger, and when he learned she left for America he was devastated and changed into a cold jerk. He fell in love with Mayu because she always loved him no matter how he acted and wanted to return her feelings. When he realized his feelings, was when Mayu went on a date with Yuuki Kakeru to make him jealous. He confronted Mayu about him and when he saw the flower he put in her hair, he congratulated her and it upset Mayu; she thought he didn't care about her. In the end, he confessed to her and kissed her.
At the end of the manga, Shinya and Mayu marry each other.