Shiika Tsukishima (月島 椎香 Tsukishima Shiika): Ann's best friend in Shimane and perhaps her only best friend growing up. Though her mother is kind and loyal to her children, Shiika does not get along with her well. She is one year younger than Ann. It is revealed through a letter written by her mother to a lover that she is the child of the affair stated above. The reason that her mother pays more attention to her and pushes her so hard it is out of guilt of the affair.