Luminous=Blue - Manga

Kou Tarumizu transfers to the high school of her idol and two time photography contest winner, Uchiho Hayama, only to find that the photography club has been disbanded and Uchiho is in a photographic slump. To revive the club and get Uchiho out of her slump, Kou decides to enter a photography contest and chooses her classmates Nene and Amane as her subjects. But it turns out that the two of them used to be a couple