Kindaichi Case Files Gaiden: Casebook of Criminal Offenders

Threatening Notes. Locked Rooms. Impossible Murders.
We've seen detectives solve them all, but how did they come about in the first place?
How does a culprit check into a hotel without taking off his mask?
How much does it cost to set up an elaborate trick?
What's the right font to use while writing a scary message?

Presenting all these and more, in a hilarious retelling of the best Kindaichi stories, but this time, from the culprit's point of view! Can the culprit successfully pull off his crimes with the young detective watching on?
Serialized in Kodansha's Magapoke (Pocket Shonen Magazine) app from 2017.

Volume 1-6 > File Series.
Volume 7 > Case Series.
Volume 8-9 > Shin Series.