ALONE IN LOVE (2006): Lee Dong-Jin (Kam Woo-Sung) and Yoo Eun-Ho (Son Ye-Jin) get divorced, but keep meeting each other at their old dating places to check on each other’s love life. Their friends push them to move on. They can only get together once they can reconcile the reason for their break up. The ending is nice but I always got a hint that the strong characters would always butt heads.

I feel like that’s every kdrama ever imo. Whether it would be an evil villain like Jin Mu holding our couple back or the dreaded evil Mother-in-Law, it’s the same in the end no?

I’d say Pinocchio for an interesting and different take for the evil Mother-in-Law trope

𝗙𝗮𝘁𝗲𝗱 𝘁𝗼 𝗟𝗼𝘃𝗲 𝗬𝗼𝘂, the Korean version with Jang Hyuk and Jang Nara. The loss of the baby and the breakup was devastating. When Mi-young/Ellie Kim returns to Korea, Lee Gun works hard to get her back.

that one with prison and Hwang Jung Eum and Ji sung

I think some of the famous fusion sageuks would fall under this - Arang and the Magistrate, Queen In-hyun's Man, Love in the Moonlight, etc.

Among modern dramas, the famous trio of Park Ji-eun's shows - My Love from the Star, Legend of the Blue Sea, and Crash Landing on You.

Just Between Lovers </b/ aka Rain or Shine is another gem from 2018 starring Lee Jun Ho and Won Jin Ah along with a host of wonderful character actors. The primary story arc involves the leads as they struggle with PTSD having experienced a building collapse as kids and find in each other a mutual loving support relationship. All the tropes are there but the rich side characters and tightly woven storytelling makes it a very satisfying, hopefully happy, ending. They still have lots of work to do.

I would agree with @miso2019 about the genre's that do this well. Fusion sageuks, fantasy, and action-y dramas do a great job of it because they are able to keep the stakes high and have external reasons why a couple can't be together right off the bat. As much as I love and appreciate dramas where the main plot is the characters growing and changing and overcoming aspects of themselves and their internal struggle, the endings usually don't feel quite as hard-won to me as when they are literally battling to be together.

My main recs are the first to dramas I ever watched: Crash Landing on You, and 100 Days My Prince (which has so far not been replaced as my fav sageuk). CLOY works so well because the whole situation dooms them from the start. It's an impossibility for them to be together in the way they want to be, so there is a lot to overcome. And I would classify it as a happy ending, despite it's bittersweetness. 100 Days has all the classic sageuk barriers to our OTP: childhood trauma, he's already married, palace politics, war. You know, the usual ;)

I'd also add Live Up to Your Name (and probably other time-slip dramas that I haven't seen) in which the OTP is separated by literally hundreds of years. If that's not a barrier to overcome, I don't know what is. My only reservation here is that you don't get to see them for very long in the happy ending. I could have used another 5-10 minutes of happiness at the end of this one to really sell the reunion. But still one of my favorites.

Hum, it's kinda a spoiler to answer to this question 😅

The King's Affection : The FL was torn between her duty and to live as a woman. The love story complicated things for her but helped her by making her stronger.

Bossam:Steal the Fate.
One Spring Night
20th Century Boy and Girl.
Ruby Ring.(While they didn't get their happy ending as in getting together, they got closure).
100 Days My Prince
It's Beautiful Now (The middle child couple had this very delicate complicated struggle but came out victorious).

I agree with some of the titles mentioned here: Crash Landing on You, Fated to Love You, Queen Inhyun's Man, 100 Days My Prince.

I would add:
1. Extraordinary You - our OTP had to fight their way back to each other in a world that saw them as disposable, with one character "meant" to be with a different partner, and with a godlike presence actively punishing and pulling them apart.

2. Princess's Man - this OTP fell for each other early, but had to work through misunderstandings and being born to opposing factions, all while political scheming and treason and murders are happening around them.

W - Two Worlds’s ending is about as hard-fought as a show can get.

Moon Embracing the Sun, the entire drama was built around the theme of a hard fought battle to win happiness for the chosen couple. But, beware that happy ending came at the expense of very sad endings for many characters. I would add Dong Yi (sageuks and fusion saeguks seem to excel at this).

I haven't watched Alchemy of Souls yet but definitely on my list when I'm in the mood for period pieces again.

The most recent hard-won drama I finished was Bravo My Life. There's nothing extraordinary about any of it, and the narrative isn't particularly great, but the happy ending was so deservedly won that it's worth a mention. Plus, the two kids in it are exceptionally adorable, for anyone that appreciates good family dramas.

"Secret Love Affair" doesn't have a conventional happy ending, but it was perfect, and felt hard fought and earned. The pairing had to overcome tremendous conflict, both internal and external, but it never felt contrived. The writing is amazing throughout this drama, and even with the 20 year age difference between the leads and the fact that the FL is married, I absolutely believed the OTO was it for each other and deserved to be together forever.

I'd also recommend "One Spring Night" even though you may have the same (culturally dictated) response to the central obstacle as I did, which is that the ML is a young, single father whose former partner a) was never his wife and b) left him after the child was born. There were definitely times when I just could not understand the depth of people's prejudices against him (he had a kid with his girlfriend--what's the big deal?), but it amounted to a great deal of struggle and conflict over which the couple ultimately prevailed. The ending is lovely and satisfying without being too much.

Like others already said, any sageuk HE is a very hard-earned one - technically. Sometimes it doesn't feel so though, thus the "technically" tag, but that's the topic for another time.

The Tale of Nokdu - it has all the elements from request above: likeable OTP madly in love with each other, life and death stakes at every turn, strong feeling of doubt that they'll eventually make it and a very happy ending against all odds. Actually this one has the HE so complete that it feels kinda unreal and jarring after all the angst and tragedy. You'll also probably want to shake some other, less lucky OTPs and yell "Why couldn't you do the same thing? See, it works!" at them after finishing it)))

For non-sageuks (since I've got a written blessing to continue advertising this drama left and right) - Happiness, duh. It's literally in the title))) This one may feel a bit abrupt/forced due to slightly rough pacing/editing of the finale, but it's still SO satisfying! Any other ending, no matter how polished, would've completely ruin the whole story and its core message. Same full marks as TToN above.

Another Miss Oh/Another Oh Hae Young/Oh Hae Young Again - oh boy, this one... Let's just say that it takes the crown for character development aspect - you're not gonna necessarily like OTP or root for them that much since the very start, because those are deeply flawed people doing a lot of sh... deeply wrong things to each other, themselves and pretty much everyone around. It gets better though - THEY get MUCH better, supporting characters also mostly get better and ending is Hollywood-esque level and style of happy. Just remember - this is NOT a romcom, not even close!

Pretty sure I forgot some, but it's past midnight and I still not fully recovered from the cold I started new year with, so I'm gonna be lazy and stop here with a suggestion to discuss not-so-real happy endings next time. Now that's where I can name MANY titles^^

Queen In-Hyun's Man
Healer
Go Back Couple
Familiar Wife

And some older ones:
My Girl
Successful Story of a Bright Girl

Chicago Typewriter: Getting to a happy ending was the work of more than one lifetime.

The Princess's Man - an oldie. Its a smash up of Romeo & Juliet, Count of Monte Cristo and King Richard III, with some portions of the story based upon real historical events. A very hard fought happy ending for the leads.

Wow, you want the biggest spoiler ever.😆

Anyway, I would recommend Flower of Evil. Trust me, they had to fight big time to have a peaceful life.

Also:
W
Come and Hug Me
Happiness
Hello Monster (the ending wasn't "happy" for me, but I think people liked it. Idk)

King 2 Hearts
Heart 2 Heart

Saebom and Yihyun who loved each other fiercely and fought zompires together in ‘Happiness’. A part of me is still not sure that Yihyun survived as that last scene just seemed more like a dream.

Not mentioned in the comments (so far) is Our Beloved Summer (Choi Woo-shik, Kim Da-mi).

If I'd watched OBS ten-plus years ago, I think I would have enjoyed it less or found the lack of action/adventure boring or too slow. However, at this point in life, I enjoy shows that explore a character's angst, motivation, and insecurities . . . as long as they lead to some actual growth in the end, and this show delivers that.

It may not meet the classic definition of "hard-fought" in the "literal fight" sense, but it was undeniably a painful struggle for the leads to overcome the things that had driven them apart in the first place.

Side note: I was very amused to later learn that Choi Woo-shik and Park Seo-jun had chatted about this role in their In the Soop: Friendcation junket. Specifically: Woo-shik also said that he cried a lot while filming Our Beloved Summer and Seo-joon responded that the strong emotions he felt showed in the drama. He also teased, “It also means you’re getting old.”

Pulling a happy ending out of the hat? My first thought was 'Mother' (2018), the Korean version. I understand the Japanese version ended somewhat differently.

COME AND HUG ME (2018).
THIRTY BUT SEVENTEEN (2018).
Both dramas take you on an emotional ride but for me one thing that separates them from other dramas is the last scene in both. The highly satisfactory endings for both dramas were unusual and gutsy on part of the directors. I will leave it at that so as not to spoil even more.

It’s Okay, It’s Love (2014) — Mental health issues are the main barrier keeping apart the OTP. The show does a great job of de-stigmatizing and humanizing mental illness.

Are You Human Too? (2018) — A lot of seemingly insurmountable obstacles for our OTP, not the least of which is that one of them is human and the other is a robot. The show does a terrific job of exploring what it means to be human and the importance of being loved for (rather than in spite of) who and what you are.

Some happy endings which weren't easy to achieve at all:

- The best hit / Hit the top.
- Live up to your name.
- The Nokdu Flower.
- King of Baking.
- My Holo Love.
- Because it's my first life.
- Happiness.
- Just Between Lovers.
- Secret Garden.
- Rookie Historian.
- Abyss.
- Train.
- W: Two Worlds.
- Extraordinary You.

In all of them, main couples (and we with them) have to endure some hard times before a happy, sometimes rushed, ending.

If I were to pick one drama with a hard-fought happy ending, it would have to be Come and Hug Me. How much harder can it get to reach happily ever after when the entire family of your one true love is viciously murdered by your father right in front of her eyes?

"The Princess' Man" a hard-won happy ending
"Crash Landing on You" almost the only option for a "happy" ending