In the thirty-first century, science and technology are highly developed. She had grown up in a slum as long as she could remember, but she discovered that in addition to her unusual talents, she also had an inseparable fate with the hot weapons of the new century... Is being transformed into the ultimate weapon just a game? And the No. 1 Player in the game who can never be surpassed even with all his strength, the suffocating killing sword that weighs on his heart like a thick fog, what does it look like in reality? Isn't that gentle angelic and beautiful dawn light really a human being? In the dark, fate pulls them, what bond will they have? Not completely lost in the sinful city...