Spoilers ahead! This is about a guy struggling with school when his sister comes home from college with a boyfriend to act as her brother's tutor. It isn't long before the brother falls for the tutor and confesses his feelings for him. Here is where the spoilers come in: the tutor doesn't really know how to respond so they decide to spend time together and get to know each other better. This leads to a light-hearted and sometimes funny series as we get to go along with them hanging out.
The problem, the relationship question of what they are is never decided. They decide to leave things as is, just two guys hanging out, which they plan to do for the rest of their lives! That's how it ends! Nothing is resolved and the viewer doesn't get any resolution to the main storyline.
I'm not sure quite how this one would be classified, it's not just bromance as the one guy is in love with the other, but it never tips over into being a romance either.
It is enjoyable and moves at a good pace, but ends without bringing the story to a close, so it is a bit of a disappointment.