Elderly Sister 'Chika' worrying about an inexperienced younger brother with a little Sei knowledge. In the atmosphere that the younger brother talks about the Sex of the parents who have watched it in the seat of the meal of the family pleasure of home life last night, and is awkward. Chika who had an obligation to say to teach a younger brother knowledge about the Sei well tell me with own body about the body of the woman. From how to put condoms to Sex….
