Changmin, an ordinary boy... or so people would say. On the outside, he seems like an innocent boy who's never been in something ever related in violence. In fights, he would just surrender or accept the blows. That's the point of view for his friends and neighborhood. In his own world, his second world and life, he's unbeatable. He goes on missions to go out to assassinate people, takes on the most dangerous missions that even the best leagues don't accept to. During his missions, he encounters another man on his opposing side. He looked so cold at first glance. In the end, Changmin retreated leaving the man, Jaejoong.

In his first world, Yunho, his best friend who spaces out a lot, doesn't know this secret either, but he has his own. He's a fighter himself but loves Changmin as well, yet he knows knows not of these secrets... So neither of them knows each other's other lives. Yunho's job is to protect Changmin, yet he doesn't know the reason why. It was just his mission. They're actually in the same agency, but they never see each other because of the time and meetings set by the agency. They don't want them to know any of the current position both of them are in.

Jaejoong, the so called 'cold-hearted', is a spy. He's the opposing side of Changmin. His background is hidden quite well. No one in his neighborhood even dares to approach him.... Until one day, Changmin, the so called 'innocent', accidentally approaches Jaejoong because he was hiding. He's quite shy, that's the reason why he wanted to be a spy, to be hidden and away from others. After their encounter, Jaejoong starts having feelings for Changmin.

Quarrels of love and fights of death. Turn outs.... Unknown..... Who knows what will happen? ... It's a wild chase...

Characters:

Shim Changmin - C.N: MAX

The Innocent and Cute, but Violent and Deadly.... Who knows what kind of secrects are hidden...

Kim Jaejoong - C.N: HERO

The 'Cold-Hearted', yet innocent and shy. Evil once in a while... But Shy.

Jung Yunho - C.N: U-KNOW 

Caring, but Spaces Out Too Much... One Day.. Who Knows? It Might Get Him Killed.