Blue Reflection Ray

Both are about magical anime girls going through emotional struggles, and their settings have equally surreal imagery. 

Both focus on the friendship between two magical girls. One is more cheerful and has short hair, and the other is more reserved and has long hair. 

Aside from being a magical girl anime with some shoujo-ai elements, both have the same character dynamics as well. With it emphasizing the idea of young girls having to learn the importance of one's passion while forming bonds and relationships with each other through several hardships and difficulties that they encounter.  

Similar in terms of their premise, having high school students form a connection with one another as they strengthen their bond. A bond that deeply introduces the concept within the difference between platonic attachment and romantic attachment, utilizing the said concept that highly influences its plot. As for my opinion, I think they are similar due to them focusing more on the character-driven aspects than the plot-driven ones. Moreover, both have the same gloomy, dramatic, and angst atmosphere with a background that is pretty much the same if it wasn't for the genre (since one utilizes fantasy concepts while the other uses sci-fi ones). In any case, if you're looking for a series that deals with relationships more than anything, then I recommend this series to you. read more 

Both are about magical girls whose powers are themed around emotion. The Reflectors focus their emotions into their rings to transform, while the emotions of the girls in Black Rock Shooter become alternate personas in the mindscape. The main protagonist (Mato in BRS, Hiori in Blue Reflection) is a cheerful and pure-hearted girl, but is also forcing herself to be this way, and ends up carrying the burden of her friends’ negative feelings. Hiori trying to save her sister is similar to Mato trying to save Yomi. Both have a special element that carries emotions in humans. In BRS, it is an alternate persona, and in Blue Reflection, it is a crystallized flower called a Fragment. There’s even an alternate dimension that holds people’s emotions. The Otherworld (mental world) in Black Rock Shooter, and the Common in Blue Reflection Ray. Both worlds have their own unique style associated with them.  read more