A girl in a maid uniform came to Yokoya Hitoyoshi's house looking for a job. Her previous job was an assassin, and she is skilled in all the deadly arts, but she's a complete beginner at housework. Hitoyoshi was confused by the strange request and sent her away. But then she saved Hitoyoshi from a deadly accident, and he thought maybe they can make this work?

This is a story about a maid who was a cold-hearted killer learning about new emotions. A maid who lived a lonely life in the underworld finally finding family. The start of an enjoyable daily life.