Waking after five years, Reito is the second "Number". Unlike the world's expectations, he refuses to "mate" indiscriminately, choosing instead to search for his missing childhood friend, Elisa, while investigating the virus's origin.
: Represents the "noble" path, focusing on romance, science, and uncovering the potential political conspiracy behind the virus.
The story begins in 2045, following Reito Mizuhara, a young researcher who enters cryogenic sleep to wait for a cure for his rare disease, "Cellular Sclerosis". He awakens five years later to a world where 99.9% of the male population has been eradicated by the "MK" (Male-Killer) Virus. Reito is one of only five surviving men in Japan who possess immunity—an immunity linked to his original disease. Core Conflict: Duty vs. Devotion