The main character, and student at My�j� High School. Because her parents live over an hour away, she decides to stay with her aunt Chigusa who, unbeknownst to Kasumi, has turned her home into a boarding house for four male students at the same high school. After Yusaku walks in on Kasumi while she takes a bath, she is troubled because she wants to remain faithful to Katsuhiko, her boyfriend. The progress of Kasumi's feelings toward Yusaku is the central story of the series. (Source: Wikipedia)