In the early 1980s, rumors begin to circulate about a new entertainment medium called "D Movie," which allows people to immerse themselves in a world of virtual reality. As D Movies gain traction, a trend emerges of disaffected young people taking permanent refuge in the virtual world while abandoning their physical bodies to atrophy. To retrieve these so-called "Sinkers," Japan's National Public Safety Commission establishes Public Security Division Four, nicknamed "Diamond Dog". (wiki)