Rie (理恵,Rie) was one of Sojiro Nishikado's flings. They slept together at least once. She appeared to harbor deeper feelings for him than he did for her.
Rie and Sojiro, possibly met and slept together previously. On one such occasion, Rie asked Sojiro who was his favorite girl. When he replied "it's you", she asked if he was serious and if he would stop seeing other girls. He replied "uh-uh".