It was announced on the official website of Trickster: Edogawa Ranpo “Shounen Tanteidan” yori that the series will get two-episode prequel OVA, to be released as an individual BD on December 22, 2016.
The first episode will revolve around Akechi and Kaijin Nijuu Mensou, and the second episode will be about Shounen Tanteidan before Kobayashi and Hanazaki meet.
Trickster is based on Edogawa Ranpo’s Shounen Tanteidan novel series from 1937.