Kyoko, a kendo master and friend of the mother, returns after a long absence. Her sudden visit stirs deep emotions in her son's friend, Yuya, who feels a rush of nostalgic longing from his youth. Struck by her timeless beauty, he struggles to contain his quiet excitement. Sensing his shyness, Kyoko teasingly kisses him, surprising them both. But the act only fuels Yuya's pent-up desire, driving him to secretly slip into her bedroom. What begins as playful affection soon blossoms into a passionate, forbidden romance between the two.