Five years ago, a boy named "Nightmare", the No. 3 Killer of the well-known assassination organization "Korstormo", gave up the assassination mission for his lover and fell into the cliff, taking with him his mysterious identity and the pistol that represented the name "Nightmare" - "Silver Wing"...
Five years later, in an unknown town, an organization composed of bounty hunters is quietly forming.
And a conspiracy also kicked off behind everything...
＊＊＊＊＊
The background may be complicated, but Xia Xia will work hard for her self-challenge. There are many pitfalls, so we need to fill them slowly.