While several of the girls investigate Vatlers ship afloat, Akatsuki and Himeragi wake up alone in the school gym with no memories of the day before and no explanation for why they were asleep on the same futon and why Himeragi is wearing an old-fashioned school PE uniform with bloomers. A bloody baseball bat and missing weapon soon deepen the mystery as assorted forces race to solve the mystery of the empty boat, the bloody bat, and the purple bra in the MCs pockets!

It was officially announced at the Dengeki Game Festival 2015 event that Strike the Blood will be getting a two-episode OVA series to be released at the end of 2015. The OVA will be an original story written by Gakuto Mikumo. (Source: MAL News)

Fifth season of Strike the Blood.

The second season of Strike the Blood which adapts three arcs from the 9th, 11th, and 12th light novel volumes.