Hiroshi visits his girlfriend's family home in the countryside to formally ask for her hand in marriage. Unbeknownst to him, his future mother-in-law is actually a remarried woman—youthful, beautiful, and highly intelligent, making her the perfect stepmother. That night, out of kindness, she allows Hiroshi to stay overnight. After her bath, as she steps out in a towel, Hiroshi can't help but be captivated by her stunning figure, his heart racing uncontrollably. Unable to sleep as the night deepens, he wanders the hallway and catches glimpses of her bedroom. His suppressed desires begin to swell, growing hotter and more intense by the minute…!