Black Gate: Kanin no Gakuen

Narifumi Hosokawa prepares for his high school's culture festival with the Kadomori twins, Shizuku and Kasumi. While everyone is distracted, Shizuku decides to open a mysterious gate through the use of magic and travel to an alternate world. She has broken the oath of her family's heritage, as to protect the Black Gate from those who seek the enormous power that lies within the world. The remaining defenders of the Black Gate, consisting of female students and a female teacher, must travel through to the other side and return before any distruptions come to either dimension. However, Narifumi accompanies the group and Shizuku is waiting for them with some new allies.

(Source: Anime News Network)

Episode List (2)

Public Sex 79% Female Harem 79% School 60% Twins 60% Isekai 60% Group Sex 60% Male Protagonist 60% Fellatio 40% Boobjob 40% Yuri 40% Rape 20% Swordplay 20% Cunnilingus 20%