Teruha's grandpa was an amazing detective, and she has dreamed of following in his footsteps. When he passed away, Teruha was still a child, so another relative inherited his detective agency. Now she's in middle school, and she's determined to build up some detective experience to prove her worth. With her friends, she's going to try to start a detective club, in order to solve smaller and larger cases around the school. The manga is partially in 4koma style.