namopanik

After a second look at the synopsis I can see where the confusion is coming from. It's not all fluff. Here's the least spoilery additional info I can come up with:
Won's mother comes from Yuan, so he's not trusted as an heir to the throne and his father shuns him as a halfbreed (and fears him as a future rival). There's a strong opposition against him in the court too.
He makes an impression on Rin, who befriends him despite his family's animosity towards the prince and stays as his bodyguard and close friend, helping him to sneak out the palace to observe common people. That leads them to witnessing a tragedy one day - here lies the connection with the girl and a root of a possible conflict.
San is a daugther of a wealthy nobleman. Soon, a marriage ban will start, so other family plots a scheme to meet her and make her fall for them before it happens. They aren't afraid to spill blood. San manages to make it alive, but she has to live in hiding from now on, switching places with her maid (a rumour was spread she's terribly disfigured after the accident) and leaving the city. She stays in a remote place run by a freethinking fallen high official of the court, where she eventually meets Won and Rin years later.
So yeah, there's more to her than just being beautiful and rich, appearing one day and having good time in their company.

You're not alone. I only mourn the lost chance of doing it as a fantasy segeuk, because you can never have enough of those, but characters' types and storyline could only improve by catching up with 2017.

but it's still pretty, whatever it was.
And hey, it's all preproduced! We don't have to fear a drop in quality due to tight schedules. Yay for more pretty things to come!

I replayed the forest scene and I think you're right. That gold lighting, lack of steam coming from people's mouths and the fact that the substance doesn't melt fooled me.
But in scenes at the play ground it looks more like petals.

I'm so glad this show doesn't try to mine out gender bender and mistaken identity hijinks despite 20 (normal) episode runtime. I could imagine it lasting much longer in other drama. Kudos for the girl's family being quick thinkers and Wang Rin aready knowing who she really is too. Also, childhood arc done within episode 1? Count me in.
/I'm even gladder that we start with main characters that are already nuanced and seem to be more than meets the eye, and not with your usual growing space for future character development.

me too, but maybe that's a Pavlovian reaction to bamboo forests. Do you know what was that thing flowing in the air throughout the whole episode (but not in the end, because that was more plausible as a snow)? Some kind of a pollen?

I don't know what browser you're using. Just google something like 'how to block pop ups [your browser name]' and it should bring you to a page of the extension. I'm using Firefox, so it's https://addons.mozilla.org/en-US/firefox/addon/popup-blocker-ultimate/ for me, but I'm sure there must be others with a recent influx of pop-ups rendering many sites unusable. There should be a big download/install button, you restart the browser and voila! Truly a new quality of life.

So he sings too, that's nice. Five years of solid performance and a very recognizable role and people still consider him an idol even on this page. Huh.

Have you tried seeing him in Flower in Prison? The drama is long and repetitive, but he's good there too.

Ok, so I don't know the source material and only saw episodes 1-2, but it's not bad at all. Yoona is doing fine (and I daresay she wasn't the cause of K2 downfall, the existence of romantic plotline itself was). Once she's given something more than just looking pretty/ethereal or crying, she has a spunk. The plot is comfortably generic so far, but serviceable. I'd expect it to go rather angsty than cheesy, and heavily focus on the love triangle. As for deeper plots - well, neither 6FD nor Deep Rooted Tree it's not, but there's a root of father-son conflict already sketched and an other party plotting. So far I have no clue how it leads to destroying the country.
Who's the other idol?

y'all need a Popup Blocker Ultimate in your lives.

thanks for replies @Nancy, @hazel321 & @Poia ! I'll check them out.

Don't both notebooks change? Crooked bandmate gets updates on HJ doodles, but HJ's gets updates from 1993/94 (the ballad), hinting the past timeline goes its way.
How the crooked ex-duo member has the notebook in the first place if HJ brought it here (erm, now?)?

/Arghh, I need that diagram HJ drew.

I have a little trust in logical time travel from someone who can't remember about stucked tear ducts or baits us with an independent heroine who needs to be rescued all the time. But notebook is a valid point. How about two notebooks being somehow connected, so the 2017 one shows changes made in the one our HJ owns?

/What purpose going back would have? If it was to conceive JH, we aren't prepared for the uncomfortability of doing it with BH while being in love with WS. We have the money (or rather no-one has it, but we found it, so it can be chalked out). Argument with WS is solved. He has nothing to do in the past other than planting things in the safety deposit box for himself, but that could have also be done by his original self who didn't know he's going to disappear (depends on what's in the paper).
// But if he was able to plant this soon-to-be expired check, he might just leave the money in cash instead. Is tricking the ex-member worth loosing 2 million wons? (sorry for edits, you probably won't see it, I'm just thinking aloud)

I can't get over how the potentiality of JH not being born is such a non-issue in the drama.

Yup. The original stayed and goes on stealing the money and dating BH, our splitted at the day of the typhoon. I can't give you an exact episode, because I binged it all last week, but there was a scene(s?) of the original timeline unraveling (around that time when they were looking for the money bag). 1994-HJ has to die to avoid them meeting one day. [No, I take it back, he doesn't have to die. Multiples aren't an issue. Two watches or two notebooks can lay side by side and nothing bad happens.] I thought they will focus more on how he died and why and maybe try to prevent it, but they didn't really.
A confirmation of a true father (and it being either original-HJ or someone else, taking away the need to travel back through time) is the simplest solution given only 1 hour left. We would need a memories-bringing typhoon to miraculously come again (twice, if we want HJ back in 2017), but we weren't given any weather related clues recently, so it'd be out of the blue, wouldn't it? They could use a pager too, and it still would be a slightly better last-minute solution than the one from Queen In Hyun's Man, but at this point I see no point in going back at all.

When they first showed it, I imagined 'to coda' handled differently (are they done with it after the piggy bank scene, or is there more to it? will see), as a mark of the final skip back to 2017 after he replayed 1994 part and escaped fooling the world in the 1994 accident. From what I understand, coda is something like a pre-climax summary, so I'd expect some part of the timelime to overlap. But now I'm not sure anymore.
I'm so excited to see how it ends and what was on the paper he found in the safety deposit box!

I second that, have you? I'm afraid they'll throw all time skipping and 'to coda' part into final week and it'll come rushed, even worse, they'll top it with 1 year separation...
But hey, wouldn't that be actually brilliant? I feel like it could go on for two or three more weeks, because we haven't even started exploring father & son (or is he?) relationship with all that love triangle going on, but fastforwarding is precisely what was foreshadowed!

I hope it's not too spoilery.
1. Misunderstandings - close to none, other than one party not confessing and other being clueless. But I have to admit I'm not very clear how weren't they dating since high school, because there was this one situation leading very much to it, but then a time skip happened and they stayed as close friends, with different partners. Bonus points for the male lead being the most straightforward guy I've seen in a kdrama so far. Once he fixes on something, he speaks up exactly how he feels without games and pretenses (but he also stays very respectful and gentle).
2. Strong love triangles - not really. As I said they have other partners at the beginning, so there are love rivals included, but they serve more as a point to expose main characters' feelings than anything else. 2nd male lead has a short arc at the beginning and it's tangled with 1st male lead past. 2nd female lead hovers around through a whole series (writers sometimes seem to forget about her or keep her for later, it happens with some side characters here…), she competes with 1st female lead professionally too (in a nasty way). But at the moment we meet her, Park Seo Joon's character doesn't care for her anymore, so she's not a strong rival either. There's an other woman for the second pair too. No danger of developing a 2nd lead syndrome for either of them.
3. No wavering. Obligatory 'what if we break up and can't be friends anymore' dilemma, but it doesn't linger.
4. Stupid decisions & useless melo. There's some drama at the very end and an ultimatum, because they differ in opinions on male lead's professional choice, but it's handled quickly.
There's some frustrating behaviour and wavering going on with second couple though.

OK, so it's not that different, but it's a fine specimen, because it's very down to earth compared to other romcoms and main characters are truly precious. Tell me what you don't like about this theme so I could tell you whether it has it or not. For example, angst from one side hiding his or hers feelings is rather low, and even though that phase may last for years (three of them know each other practically all their lives) we aren't tortured with it for very long, but only learn later.
There are two pairings and four of them are supposed to be friends, but have very little of a shared screentime. The second pair is in a long relationship (6-7 years or something?) and comes through a crisis.

and short. Thanks!

Well, the main pair gets together and villains are down, but the body count is high too. So it depends.