This is the story of a couple of oddballs (well, more than a couple) being odd together, lol. The mannerisms are exaggerated, the scenarios are outlandish, there's a whole side plotline that is five layers of silly, and that's honestly the entire charm of the series. The entire drama is intentionally silly and doesn't take itself seriously. If there's one thing you need to know about it going in, it's that.

Hwang Me Ri is admittedly unlikable for the first half of the drama, coming across as very selfish and thoughtless towards others, while Kang Dae Gu initially comes across as a leach and a slob. But as the story progresses, you begin to like and understand the characters more in spite of themselves. Hwang Me Ri becomes a more sympathetic character around the halfway mark, and Kang Dae Gu quickly proves himself to be a decent guy who's just struggled to find his way.

The story itself is very self-aware, poking fun at its characters and joyfully placing them in awkward or embarrassing situations for the viewers entertainment. The drama does take itself a little too seriously in the last few episodes, wallowing in a little too much 'woah is me' around some particular plot points that didn't need to be such a big deal (especially considering the literal dramatics of some of the drama's earlier events), but it's otherwise a solid drama that's likely to give you some pretty big, roll-your-eyes, belly laughs.

My recommendation for those thinking about watching Merry Mary is to not take anything in this drama too seriously, because you're definitely not meant to. Just go with the flow, and you'll have fun.