I'll admit it, I wasn't very impressed with the trailer, no, but the series truly exceeded all my expectations.

First off, story wise. I expected equal parts romance and mystery walking into this, they set it up that way in the first few episodes. I didn't get that, but I was still enthralled.
Would it have been nicer to explore the mystery and backstory more? For me, yes, but that's more about me wanting the side characters to have been more fleshed out. Otherwise? You can absolutely tell that the creators took a lot of care in creating an airtight story, where the past confusions, bitterness and anger plays into the present. The reveals in each episode seem obvious in retrospect, there's really only one way it could've played out, and it did exactly that way, but what made it interesting to watch was the characters.

Speaking of the characters, they were complex and red flags for the most part, I mean, I spent some episodes just wondering how on earth they could pull off all the things they did quite nonchalantly. But I'll be honest again, this was as entertaining as it was because they were that messy. All three of them, the leads. And so many side characters, but again, we didn't really get to see a lot of them.
But you still want to root for them! Most of the time, at points I didn't like any of them, but for the most part, you want to root for them. As individuals, as romantic partners, as siblings. They were morally grey and doing things that pushed the plot and their lives to be more complicated, right from the beginning and it's because the characters were written this way, that the story blossomed the way it did.
Let's address the weirdest side couple before we move on though. It was weird. Individually, those characters didn't add much to the plot any way (side characters again), but the love triangle there was somehow weirder than the love triangle between two literal twins and someone they both liked. I'll leave it at that, the absurdity and amazingness of it must be watched to be understood.

Finally, the acting. That's not true, because I did expect some good acting when I started, and I got it. Absolutely. Film and Namtan have good chemistry, they can act well, they pulled off their characters perfectly (Namtan did it twice over, lol), and so did all of the supporting characters.

Pluto truly did exceed my expectations, I did think that the episodes could have been shorter, but that would've meant the story would've been fragmented and hard to understand. At the end of the day, it was fun to watch and I genuinely enjoyed it.