Harunobu Madarame is the most hardcore otaku of the Genshiken members. He carries his obsessions to an almost dangerous degree, and will spend nearly all of his money on dōjinshi, which leaves little money for food or other living expenses.
At Comifest, he hurt his hand to the point of it being numb and swelling, but he still didn't want to leave. Although he's Saki Kasukabe's main antagonist, he gradually and secretly falls in love with her. Harunobo never has the courage to confess his feelings during the 3 years because he is sure that his feelings have no chance of getting reciprocated.
By the end of the first generation, Harunobo and Saki have become good friends.