This Boy Suffers from Crystallization (2014)

The story revolves around high school boy Ayumu Tamari who has an illness that makes him start to turn to stone when hes stressed Since he couldnt fit in with his class after repeating a year he declared that he wanted to have a Sparkly youth as well To do this he changed his hair and clothes to be more fashionable and constantly checked for popular topics to stay in the know In the midst of Ayumus life of making a facade his homeroom teacher and stoneloving geology teacher Kouya Onihara says that Ayumus stone transformation is beautiful Ayumu begins to become attracted to Kouya who starts to give him advice