Koko, who harbors feelings for her private tutor, uses various methods to seduce him. Shy and reserved at first, the tutor is directly asked by Koko, "Sensei, have you ever had sex before?" Though initially flustered, he eventually gives in to Koko's advances, leading their student-teacher relationship further. Koko's mischievous, devilish smile radiates an aura of seeking new adventures each and every day.