Shinitai Majo to Koroshitai Tenshu summary:
The owner of "McLeod's Death Shop," which sells death to wizards, lives for the purpose of saving them by giving them the death they have requested. He has sold death to any wizard who has requested it, but one day, when he was in trouble because he just couldn't die, a witch came running in...?
Note: The manga won first place in Rensai Soudatsu Ranking.