Rei is the only child of a family who owns the Yukito Shrine. She serves as a shrine maiden. Rei is a third year student and is 1 year older than most of the cast. She is very intelligent, critical, and level-headed. She can't cook, though.
Rei is a member of the Environmental Protection Committee that is headed by Misato that protects the Snow Sakura tree. She is also the top student of Sakuragaoka Academy and the school recognizes her achievement. Rei's suffers from the expectations that is put on her.
Rei smokes 5 cigarettes a day and she is skilled in mahjong. When the semester exam approached, Saki and Sumiyoshi requested Rei to help them with their study.
For the culture festival, Rei and Misato decided to tell the legend of the Snow Sakura tree. Yuuji suggested to make a movie. Rei served as the director of the movie.
On Rei's path, on Christmas Day, Rei invited Yuuji to the Snow Sakura to confess her feelings for him. On New Year's Day, Yuuji went to Yukito Shrine. Rei made him man the sales booth and she gave him a good luck charm.
Rei revealed that the school recommended her to further her studies to the prestigious Waseda University after she graduates. On the other hand, her parents want her to continue to serve the Yukito Shrine. Rei had resigned to fate. Yuuji asked her about her personal wish and she revealed that she wanted to become a botanist.
Rei is very shy about her relationship with Yuuji. She confided in Saki about furthering her relationship. Saki advised Yuuji to take the lead in his relationship.
Later, Saki advised Rei to confront her parents and the school board and voice her desire. Rei's parents refused to listen to her causing her to run away from home. She hid at Yuuji's place for the time to think. Eventually, the group supported her to confront her parents. Rei discussed with her parents and managed to get her wish. She will spend a year studying botany then further her studies with Yuuji.
Finally, she revealed that the pressure that people put on her made her take up smoking to ease her stress.