I'm not sure if this is supposed to go in the help section or not, but it's an anime-related question so I felt that this section would be better.
So, the anime I'm thinking of has a main character who LOVES the sky. He spends lots of time on the roof of his school looking at the sky, and he loves to photograph the sun. He meets a girl with long purple hair (I think?) who turns out to be a special type of being who can't go into sunlight.
These next details are spoilers about it (just a warning in case it's an anime people are sure they haven't seen.)
The main character is made out of little paper-cutout thingies that are put together and animated to make him be in existence. His sister (not sure if actually biological) re-created him and implanted the memories because he was lost. His sister controls little paper-cutout like things, and she uses them when fighting the purple-haired girl. I don't remember details as to why they dislike each other though, although I do believe all three of them lived together in the past.