Kouhei is the professor at the school of students Kaede, Kyoka and Yuki! There's a line these four can't cross. But Kaede, Kyoka and Yuki have broken through the forbidden barrier.

The girls seduce him with drugs and domination so he'll agree to take their virginity. Become Kouhei, and get it on with deliciously naughty teens...

[From DLsite English]