NSPS-987 Kayo Iwasawa, my sister's friend who made me a virgin

Junkichi, a younger brother who lives with his sister. When Junkichi returned from work, his sister’s friend Kayo was drinking with her sister. Junkichi, who was supposed to drink with him, is exposed to his sister as a virgin 30 years ago. Kayo who knew it seduces Junkichi, but Junkichi, a virgin, is at the mercy of an older woman, Kayo.