Koroshiya-san: The Hired Gun  

Mr. Hitman, 殺し屋さん The hired gun

The narrative revolves around a character known as the best assassin in Japan. He is renowned for his ability to complete any task assigned to him, regardless of its nature. His approach is straightforward - if there's an assignment, he will kill it. However, his targets have expanded beyond just people and now include tasks such as homework and housekeeping. Despite not intending to do so, the assassin always succeeds in killing the target while also eliciting laughter from those around him.