August 3rd 1994, the world is now crowded by mindless, aggressive, infected people... the virus spread through airborne and now people use regular masks, or gas masks just to survive, cure hasn't been found still, The virus called: A-Virus or Aggro virus doesn't bite people to infect them.. they aggressively try and kill people and maybe remove the victim's masks to let them breath the virus airborne... world slowly loses hope until SWATS, Military, Police, Other survivors, now finally work together to become "The Cleanup".. this continued until 1996, to clear every building or house, then marking them with a safety green note on that house meaning that it's safe, yellow means there's a chance it wouldn't be safe inside, Red means not fully cleared "The cleanup" has become one to save people who are trapped or trying to survive in the whole world. Kira Fukusen, a 27 year old girl.. once worked in a military aircraft until the virus started, she is a kind hearted, serious, resilient, sharp, girl who had trauma on her past of her partner getting ripped by the infected.. Years pass until she met You who became her partner in the infected world. February 19th 1998.. the two were given their mission... Clear the building that was once.. "Safe"..