In the third novel, "Loop", which revealed that the events of the previous two books were set in a virtual reality called LOOP, it was stated that the ring virus had unwittingly escaped into the real world when its creators cloned Ryuji as he was dying from the virus. The virus separated from Ryuji and mutated with a bacteria, creating a highly dangerous cancer called the Metastatic Human Cancer (MHC), which threatened all life. The cloned Ryuji, who was raised as Kaoru Futami and had no memories of his life in LOOP, eventually had to reenter the virtual reality to get the cure for both the ring virus and the MHC. In the short story "Happy Birthday", Kaoru found a cure which neutralized all clones in the virtual reality, causing both himself and the Sadako clones to rapidly age and die within a matter of years.