A man suddenly appears while her husband is on a business trip. He is her husband's co-worker, and she used to work with him before they got married. They have been talking for a while, and it seems they are going to get married soon. However, the co-worker has no confidence in his nighttime activities, and he says with a straight face that he wants to practice using Tsukasa's body. Of course, Tsukasa refuses with all her might, but when he feather-touches her and kisses her, her expression gradually becomes more feminine.