Three years have passed since Shihori remarried, with her husband frequently away on business, leaving her stepson, Shinya, as her constant companion. Their quiet time together brought Shinya happiness, but Shihori secretly struggled with loneliness. Sensing her emotional void, Shinya's friend Hideyoshi begins to seduce her. Though she resists at first, Shihori gradually finds her heart and body fulfilled by him. Their illicit affair grows increasingly passionate—until Hideyoshi discovers Shinya's true feelings for Shihori. In a twisted act of manipulation, Hideyoshi blindfolds Shihori and quietly brings Shinya into the room, setting the stage for a forbidden encounter.