In a world full with hitman lives a man known under the name "Simon" but his real name is Kageo. He is very tall and well built with blonde hair and is Japanese but lives in Korea. As a professional Assassin, he hasn't developed any fighting style other than his flexibility and a very special trait only he has. He was born into a family with toxic blood thwt melts and burn everything it touches but as the event came, he was left all alone with that ability which he hides

he works under someone named "Raphael" and follows his orders.