Golgo 13

Golgo 13, also known by the pseudonym Duke Togo, is a professional assassin. His age and birthplace are unknown and there is no consensus in the worldwide intelligence community as to his true identity. Most of his jobs are completed through the use of a customized, scoped M16 rifle. Golgo 13 is contracted to kill Boss Goa, the head of a worldwide crime syndicate responsible for drugs, weapons, and human trafficking.
~~ Adapted from the manga with the same name.