Rain Fall // A Clean Kill in Tokyo — Barry Eisler

JOHN RAIN KILLS PEOPLE. FOR A LIVING. His specialty: making it seem like death by natural causes. But he won't take out just anyone. The job must be an exclusive. The target must be a principal player. And he'll never murder a woman. Half American, half Japanese, but out of place in both worlds, Rain bases his operation in Tokyo, where even a crowded subway car is filled with opportunities--like slipping a pacemaker jamming device onto a victim. John Rain may not be a good man, but he's good at what he does. Reliably discreet, coldly efficient, Rain is the best hit man money can buy....

Until he falls for the beautiful daughter of his last kill.