A girl in a maid uniform came to Hitozu'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. Hitozu was confused by the strange request and sent her away. But then she saved Hitozu 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.