19-year-old private detective Rena is assigned to train the clumsy new hire Sato. After Sato is attacked on a job, they take shelter in a nearby restaurant, where owner Taeko asks them to investigate an odd taxi driver she knows named Odokawa...

Rena attends a Mystery Kiss event to see if Yuki remembers her from their high school days. While continuing their investigation of Odokawa, Sato discovers that the man who beat him up on their first job was the infamous criminal Dobu.