Busu ni Hanataba wo.

The manga centers on Hana Tabata, a girl who constantly deprecates herself, considers herself ugly, and keeps only to herself. She spends her time taking care of the flowers that decorate her classroom — but is careful to do it only in the morning when nobody is around, as she is afraid of being laughed at for being an "uggo who takes care of pretty flowers." But one day, the class' most popular guy Ueno sees her taking care of the flowers.