During the Dengeki Game Festival 2015 held last March 15, it was announced that light novel Strike the Blood is getting a two-episode original video anime. The OVA is set to release at the end of 2015 with an original story by its author Gakuto Mikumo.
Strike the Blood light novel series was first published in 2011 by Mikumo, illustrated by Manyako. It was then serialized to a manga series in 2012 and adapted to a TV series aired in fall 2013.
You can check the promotional video below: