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.
is based on Edogawa Ranpo's Shounen Tanteidan
novel series from 1937. It will also receive stage play adaptations, in addition to its manga adaptation
that began serialization in June 2016 in Magazine Special
. The anime began its TV broadcast on October 4 at 1:05.a.m. via Tokyo MX, and is also being simulcast by FUNimation Entertainment
Source: Official site
Trickster: Edogawa Ranpo "Shounen Tanteidan" yori OVA