Hongbin - Kidnapped from his grandmother's side at a tender age and brought up in an underground organisation that trains assassins. In a bid to survive, Hongbin was forced to become the best.

Taekwoon (codename Leo) - Freelance assassin. Was previously a homeless punk roaming on the street but subsequently joined the biggest mafia ring and trained under their master hit man. A natural who is so good at what he does, he became the best.

One became weary, the other despondent.

Their paths crossed.