From the original "Honor students after school" series.

Part 1: Concealed Curiosity
Moriyama-san was instantly in love when he first saw Izumi Yurako, who has recently been transferred to the city.
Having confessed and was somehow miraculously accepted by Yurako, the two start their relationship in many physical ways.
Unknown to Moriyama, Izumi is quite the nympho but goes along with her dangerous advances...


Part 2: Essential Lesson for An Honor Student
Hina Michika (Mikage Hinamachi) grew up in a rich household and attends a private girls-only's school in the city.
In this school, all the girls are sexually suppressed since there are no boys around. Even if they want to have erotic encounters, there are certain dangers with paid dating and random guys so Hinamachi-san decided to hire a tutor for ecchi purposes instead!