Kazuki Okino is an ordinary high schooler living a carefree life. He's always been close to his childhood friend, Otome Sakuragi—a beautiful girl every boy in his school dreams of being with. Because he and Otome often hang out together and get along very well, Kazuki believes that it is inevitable that they begin dating. However, Kazuki's little sister, Rinka, is dissatisfied with this possibility because she is secretly in love with him.
This innocent relationship takes a dramatic turn when Kazuki receives an untitled DVD showing Otome engaging in sexual activities with elderly men. His despair grows even greater when similar DVDs start arriving on a regular basis. As Kazuki stares in horror at the love of his life being defiled by a group of strangers, he notices Otome's demeanor gradually changing.