Synopsis
Tarou Sakamoto was considered the greatest hitman of all time. Feared by many, he stood at the top of the underground world until he met and fell in love with a woman. As a result, Sakamoto abandoned his life of crime and now works as a convenience store clerk.

Leaving his shady past behind proves more difficult than Sakamoto initially imagined. Many of his former rivals and partners do not believe that he has truly left the business and show up in hopes of taking him out. Barred from killing, Sakamoto must find creative ways to subdue his enemies and prevent them from bringing harm to his family, his store, and the small town he resides in.

(source:MyAnimeList.net)