It's an ongoing series. The author just began English translation not too long ago. So far, it's just been a few chapters. You can find it on nhentai but I do encourage to support the author. The chapters I'm showing are from BLOOM ROUND 4 AND 5. It focuses a lot on the mental state of the heroine as she becomes tortured by the perverted play of the enemy as the woman discovers masochistic tendencies as they continue to grow. https://www.dlsite.com/maniax/circle/profile/=/maker_id/RG34531.html