Gakuen Monogatari ~Ikenai Houkago~

By the end of the 20th century, women have acquired a prominent role in the human society. Entertainment, arts, and politics are increasingly dominated by women. Therefore, a special emphasis is put on educating young women, preparing them for the turbulent social life. The world's most prestigious educational institution is the Japanese Eikou High School. Becoming a teacher in that school is the highpoint of the career of the protagonist, Takigawa Noboru. But as it always happens (well, at least in bishōjo games), the moment the hero encounters all those gorgeous female colleagues and students, he forgets all about education...

[From Moby Games]