Nanairo No Shinwa七色の神話; Nana Iro No Shinwa; Nana-Iro no Shinwa; Rainbow Myth; Seven Color Myth

From Impossibility: One day, two high school students find that they are able to communicate to some of the dolls in the art room. The dolls tell them that the only reason they are able to hear them is because they are still "naive"/"childish". However, some events cause the girls to grow up and start losing the ability to communicate with the supernatural...