Tonari no Kashiwagi-san

A high school student who openly embraces his otaku lifestyle becomes interested in a moe artist named Sayane. He is seated next to a popular classmate who expresses disdain for the culture he loves. They later meet at an otaku store, where he discovers her secret: she is deeply into the same culture she publicly mocks. He agrees to keep it confidential, and the two begin secretly sharing their mutual passion. Unbeknownst to him, she is also the anonymous artist he admires.