After defecting from the tyrannical regime of North Korea, as one of their elite soldiers, he escaped to somewhere else and trained himself to fight against his evil compatriots for the sake of real justice.
He was very lucky that he met Kagura to work together at the Shinozaki Institute on hacking their highly secured documents and turning back the tide of war.
"If fighting for justice was a sin, then I'm in the world of sinner!"
PS: Changed his hairstyle.