Height 153 cm Rin is the main heroine in the story. She is the younger sister of Kyousuke Natsume and is the only female member out of the five original members of the Little Busters. She does not communicate well and is seen as inarticulate. Due to this, she is anti-social, and is usually seen alone. When playing baseball with the others, Rin is an ace pitcher, although she used to be quite a bad pitcher — her throws would go in completely unpredictable directions — until she gets into a baseball stand-off between Sasami, where she demonstrates two "super-power" pitches, where one of them is a fastball and the other one is her own version of a changeup. Rin loves cats and at school takes care of several strays; it is not uncommon for several cats to crawl onto her.

Spoiler

She is sent to another school as an exchange student, which instead of making her stronger, breaks her apart. People who played the Refrain route notice that Rin's personality completely broke apart, and she has the mentality of a little kid. Eventually, she and Riki reform the Little Busters, and Kyousuke reveals the secret of the world that he is hiding to them. After the fake world disappears, Rin and Riki save the people in the bus crash. It is hinted that after the events in the VN, Rin and Riki are planning to start dating in the future.