Kensaku to Enjin no Happy Birthday
Japanese title: けんさくとえんじんのHappy Birthday
Type: ONA
Source: Original
Episodes: 1
Status: Finished Airing
Aired: Jun 19, 2018
Duration: 41 sec
Rating: G - All Ages
Producers: Yahoo! Japan
Demographics: Kids

An entirely 3DCG Happy Birthday episode of Kensaku to Enjin. It was meant to congratulate the viewer's birthday rather than it being the birthday/anniversary of the Kensaku to Enjin franchise or Yahoo! who owns the franchise.