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.

Rena pays a visit to Donraku and Kabasawa. Sato tries to tail Dobu to get his stolen photos back, but is caught in the process.

Rena continues to try and uncover the secrets behind Mitsuya Yuki, and recruits Kanon and Sato to help her tail the members of Mystery Kiss. Meanwhile, Kakihana continues to dig himself into a deeper hole.

After quitting her detective job, Rena starts working at the same cabaret club as Imai to try and learn about Mystery Kiss's history, and in return she reunites him with a certain taxi driver. Sato learns more about Rena's past.

At the audition, Rena finally gets a chance to talk to Mystery Kiss in person and ask about Mitsuya Yuki, but her probing questions catch Yamamoto's attention. Odokawa enlists Dobu's help to rescue Kakihana.