Ever since he got married and started living with his mother-in-law Yuka, Tsuyoshi has been overwhelmed by her mellow sex appeal. Her unconscious sex appeal grows day by day, and he is nearing his limit. He loves his wife, of course... but it is also true that he is attracted to Yuka. Yuka, who is unaware of Tsuyoshi's struggles, lets loose and drinks too much at a class reunion after a long time. Tsuyoshi takes care of Yuka, who is drunk, but... he can't take his eyes off her ass when her skirt flips up...