Oliver's best friend.

While they both go to the same high school, they didn't actually share any classes their first year and met instead as coworkers in the same cafe. They bonded quickly, but later Oliver left for a higher paying job at a sandwich shop and they lost their only time together. They searched for each other at school after that and Oliver invited Andre to his club so they could still have chances to meet up.

Andre isn't really interested in super heroes, at least not much. He is, however, deeply interested in psychology, and there are plenty of ways to explore that in super hero movies. Once Oliver had Andre watch Spiderman 2 and Andre found immense joy in pausing every two seconds to psychoanalyze the character's facial expressions (Oliver was pissed and it was hilarious; he didn't even realize Andre was parodying him at Super Hero Club, pausing every scene to spout off some tiny trivia or fanboy knowledge).

Andre feels a little uncomfortable at their fancy private high school, since even as a city school most of the students are white (it's an expensive place). He often feels like an outsider, and feels much more comfortable working where he's often around people from many kinds of backgrounds. Oliver's never made him feel like an outsider though; he wishes they shared some classes together.

Series Related

The Adventures of Justin Time and Marmalad
Purely a background character, would only show up during times Oliver is at school.