I'll preface this by saying that I enjoy all your characters as always, and love just how varied you can make so many different characters and how easily their personalities and little quirks come through.
Since you asked about them specifically, I'll say that I'm really enjoying Haru's threads so far. You do such a great job of capturing his weirdness, and I applaud your ability to keep threads going, especially since he's a relatively quiet guy. I'm excited for when he actually does turn into a mermaid, as I'm sure it'll be hilarious.
For Mako, I think you do a great job of capturing his particular brand of awkwardness and his unique sense of humor. I'd love to see him getting more involved in a kind of Charming line of thought, in which his more Upholding the Law nature can come through, and/or his wish to help others (perhaps anyone who might remind him of Bolin?). He's a lot of fun and I'm loving your take on him, and can't wait to see more of him.