Yutaro Tamba is an ordinary student at Yoru Yoru Gakuen who just likes the occult a little bit. On the last day of school in summer, Yutaro is suddenly visited by his childhood friend. Suddenly, he receives an invitation from his childhood friend to go to the school building at night. ......This was the beginning of everything. The night started a "dense erotic" "night sex class" with the "pure and innocent girls" who haunt Yutaro's daily life!