His character is the arguably the least-defined of the group, however we know some of his quirks. For instance, he has a collection of Futurama figurines, and likes playing videogames. We know that he at least occasionally writes songs with Zack, but Zack feels he gives in too easily. He suffers from a number of ailments, including asthma, hypoglycemia, deviated septum, and rosacea. He wears glasses.
In one storyline, Brian wrote a song called "Lane," while Zack and Lane were dating, though he never showed any romantic interest in Lane. He was however interested in Kyon (played by Susane Lee), a foreign exchange student taken in by Mrs. Kim after Lane moves out. She and Brian are seen flirting multiple times throughout the last seasons.