Seven years after graduating from high school, Yui, who is now a Yui woman, receives a letter from her former homeroom teacher, Sasaki. The letter from Sasaki, a teacher she admired, is what leads Yui to visit her alma mater with her husband. She reunites with Sasaki in a classroom full of memories, but something happens that makes her remember the rape incident from her school days that she had kept hidden deep in Kokoro... Then, Yui happens to Yui her classmate, Hayashi, and he tells her the unknown truth about her former teacher and the truth about the rape...