Souta-kun no Akihabara Funtouki

Meet closet "otaku" Sota, a seemingly normal high school student with a secret obsession for the dog-eared anime character Papico. During one fateful trip to Akihabara, Sota’s life takes an unexpected turn when the crazed owner of a collectibles shop forces Sota to "come out" in all his fanboy glory.

From http://gomanga.com/manga/iotaku.php