18+ Dokyuu Hentai HxEros

When the alien Kiseichuu descend on Earth, they have one goal: eradicate the human race. They do so by feeding off the very passion that drives humans to reproduce, their H-Energy! Retto Enjou is recruited onto a team of elite, sexy superheroes assembled to save Earth. Living in a dorm with the four beautiful women of the HXEROS team, Retto finds himself caught up in a web of erotic intrigue where the whole world is at stake! Extraterrestrials and ecchi will collide in this ultimate battle for humanity's debauchery!

(Source: Seven Seas Entertainment)

Included one-shot:
Volume 3: Haikei, Hannibal (Dear sir Hannibal)