In 2030, nuclear war broke out over the environmental pollution issue. Many people lost their lives due to radioactivity. The people, who survived the barren Earth, started the "Megaro Earth Project" to save human existence.

In a last hope for survival against nuclear war, a city was built in a dome in order to save civilization. Gimmick, a mysterious man who leads a secret organization called "Black Widow", is planning to obstruct the implementation of the "Megaro Earth Project". In order to oppose Gimmick's organization, members of the counter terrorism group, along with lady sniper "EL", were formed.

Unfortunately the group has not been making much progress with their tasks. As a Sniper with the highest rank of SS you have been recently transferred to the group to assist with their task of opposing Gimmick while also doing your best to keep your skill and overall rank a secret from your peers.

Expect the worse and unexpected....