Mamiya Kyouka

What she calls the protagonist: Ryouta-kun

The gentle older cousin, an English teacher and the homeroom teacher of Ryouta's class. She also helps managing the lost & found service at the school.

Kyouka takes her job seriously and has a honest personality, which has made her popular with both her students and coworkers. She takes her students into consideration, and is especially concerned of Ririka who has a hard time making friends.

Kyouka loves Ryouta more than anything and tries her best to show her appeal to him. She even wants to marry him (since it's okay to get married to your cousin) and has even received approval from her own parents. Especially lately Kyouka has been keeping her eyes open for all possible chances.