Sexual Desire Virus / Kansen: Inyoku no Rensa

That same "first part" from the series of stories about a mysterious virus (released by the company SPEED as a visual novel) that causes an incredibly strong sexual desire. This time, a group of students who were locked in the institute were exposed to the mysterious virus. In the end, everyone gets infected, and everything turns into a continuous orgy. 

 

 

#1  Kansen: Inyoku no Rensa - OVA (2 ep.), game adaptation, 2009
#2  Kansen 2: Inzai Toshi - OVA (2 ep.), game adaptation, 2010
#3  Kansen 3: Shuto Houkai - OVA (2 ep.), game adaptation, 2010
#4  Kansen 5: The Daybreak - OVA (4 ep.), game adaptation, 2012
#5  Kansen Ball Buster The Animation - OVA (1 ep.), game adaptation, 2013