It has been announced through the official Twitter account of Dengeki Bunko of Kadokawa, that the Strike the Blood light novel written by Gakuto Mikumo will end in volume # 22 which will be published on August 7
This light novel debuted in 2011 and inspired an adaptation to the anime in 2013, followed by a second season in OVA form in 2015 and 2016 - 2017 and a third season in OVA form which aired between December 2018 and September 2019
The fourth season also in the form of OVA aired 2 episodes on April 8, the remaining episodes will air on July 29, they were scheduled for June 24, but there was a change due to COVID-19