Shinya, one year older than Kiyomi, the daughter of Yukie Mizukami, has been her childhood friend and private tutor since they were kids. Yukie has always treated him like a son, and Shinya has cherished her like a mother. However, as the years passed, Shinya began to realize his feelings for Yukie went far beyond a simple parent-child bond. Within him grew an intense desire to possess her completely, gradually transforming into sadistic urges. Driven by obsessive love, his heart gives birth to twisted desires that grow uncontrollably and irreversibly.