This movie is considered as an alternate ending of an alternate story of the series Kamen Rider 555 (2003), in which Smart Brain and the Orphnochs have won the war and accomplished their goal of world domination with 90% of Earth's population being Orphnochs while the human race is diminishing to near-extinction.
At the time, the film received a Guinness World Record for the most extras to appear in a single film, which is said to have a total number of 10,000, but soon grew to 90,000, and eventually 99,000.