Sota, who harbored secret feelings for his young and beautiful stepmother, Saki, realizes he left his phone behind while visiting his friend Yosuke's house and returns to retrieve it. Finding the door unlocked, he heads toward Yosuke's room—only to witness an unbelievable sight: Saki and Yosuke having sex. The woman he adored was involved with his friend all along. Overcome with rage toward the mother and son who stirred such painful emotions within him, Sota vows revenge. This shocking twist promises an intense, heart-pounding experience.