Yuto resents his mother Yuka's remarriage. Having lived together as a close-knit pair, he cherished their time as mother and son, seeing her not just as a parent but as his emotional anchor. However, witnessing Yuka's relationship with her new husband triggers intense jealousy and inner turmoil within him. As Yuto desperately seeks love and connection, Yuka feels torn—hurting for her son while also awakening to feelings not just as a mother but as a woman. Despite growing awkwardness, their suppressed emotions begin to surface, leading them into a forbidden, incestuous relationship filled with tension, desire, and humiliation.