Rokugatsu no Hengen-san

From Blissful Sin:

In the old and cheap boarding house, Fukujyu, Fine Arts student Haru finds himself rooming with the quietly unconventional Natsu. A shy and reserved young man, Natsu is often the butt of jokes for his classmates and teachers. When nasty rumors about Natsu's past begin circulating among their acquaintances, Haru's tepid friendship with Natsu is sure to be tested.