Kizaki Rena

She is the best friend of Shion and the main character. A familiar sister. She has been married for 4 years.

She left her hometown when she got married, but their relationship became strained, she is now living alone in an apartment.

She is a cool and mature woman, but also has a little devilish side. She loves the main character as if he were her younger brother, she sometimes teases him a little sexually. She also enjoys his reactions.