Alderamin of the Sky (Manga) was somewhat of a disappointment for me. I started reading it after watching the anime, and I was expecting the manga to be better. To my surprise, I found it to be worse. The anime was far more fleshed out with the story and the characters, along with extra content that the manga needed. Also, some events seemed completely meaningless in the manga in which the anime had made meaning off (ex: Kanna). Overall, the manga I found to be just OK. However I am not saying the manga is bad, it just missed my expectations. My recommendation is toskip the manga and go straight to the anime, which I consider superior. I can't say anything about the light novel, as I have not read it.