The word detective is not unfamiliar in the 21st century, but in most people's perception, detectives still exist more in TV and novels. Three young people who are keen on reasoning and solving crimes opened a shop specializing in repairing musical instruments, but their real profession is detectives, but no one would pay attention to them even if they clearly said that they were detectives. Finally one day, the first customer came to the door.
Concept: Every little thing in life needs to be discovered carefully, such as the warmth and warmth of people's hearts and the changes in scenery.