On her first day of junior high school, Mato Kuroi meets Yomi Takanashi. Though Yomi is initially taken aback by Mako's straightforward personality, the pair quickly becomes friends and begin to spend time together daily. As a sign of their friendship, Mato gives Yomi a cell phone charm—a blue star, identical to her own. However, when the two enter their second year, their relationship starts to change. Placed in a d...