Sex X-Files: Estrus Virus

A woman on her way home was attacked by a mysterious beastman and died after being violated. Since there were many suspicious aspects in this case, it was handed over to the Research Institute, which specializes in handling strange incidents, and was investigated by researchers Tatsuya and Maki. The two collected cells from the victim, and surprisingly found that the woman and the victims of three other similar cases had the same virus. The two do not know where the virus originated from, but they are certain that the victims were infected and even died due to sexual intercourse with people who had the virus. What's even more terrifying about this virus is that it can bring the dead back to life and infect others...