Remarried spouses each bring a child into the union—husband Shoji becomes intensely sexually dependent on his stepdaughter Saeko, while wife Takako grows obsessed with her stepson Satoru. Their twisted relationship spirals further as the husband's younger brother and his lover become involved, pulling the entire household into a vortex of distorted desires. Amid intricate personal ties, a story unfolds where love and lust dangerously intertwine.