Arisa (16) is reunited with art student Masaki (20) after three years. She lives with her mother Saeko (39) and maid Aya (22). Masaki and Arisa are half-siblings, and his mother was a mistress. Saeko, who had taken care of him, commissioned him to paint a portrait. That night, he witnesses Saeko and Aya embracing passionately. Masaki struggles to make progress on the portrait, and Arisa gently comforts him. Saeko, displeased with the two of them, begins to provoke Masaki. Masaki recalls the humiliating days of the past when Saeko repeatedly assaulted him. Still unable to paint, Masaki confides his past to Arisa. Arisa then confesses that she herself had masturbated while watching Masaki being violated. Their suppressed love overflows, and the two embrace. Driven by desire, Saeko forces the submissive Aya to confront Masaki. He resisted but seeing Aya writhing in agony, he gradually lost control and began to desire her. While secretly watching, Arisa indulged in self-gratification.