A girl who secretly estrus when she sees a boy's erection at a school that has become a co-education from this year. And I can not stand it and have sex after school! A female teacher who happened to see a student doing naughty things in such a classroom. A boy student who saw a female teacher who was in heat when he saw it. A girl student who saw a boy student who was in heat and erected. Everything is connected by erotic lines! The fascinating estrus chain never stops!