This may be the easiest "just pick one" for me: Forest of Secrets, either or both seasons.

This one is too clear for me and I agree 100% with mistyisles. That friendship between Na Hee-Do and Ko Yu-Rim of Twenty Five Twenty One was so ridiculously impactful. I can't even think of a close 2nd place.

All the housemates of Belle Epoque in AGE OF YOUTH S1&2

Dang. I will never be able to pick. Be it the growing up together friends of Reply1988 vs the friendship that has stood the test of time in Hospital playlist vs a friendship that is forming and showing signs of lasting in Weightlifting fairy vs a friendship that feels like home in Be Melodramatic , I will never be able to choose. So I pass.

For this prompt, the first one that entered my mind was the platonic friendship between Shim Woo-joo and Yoon Joon in Call It Love.
During the drama, I sort of lived in fear that it would turn out that he had feelings for her (it was clear that she would not for him), but happily no.

The scene near the end of Episode 7 where Woo-joo is figuring out what love feels like to her, and he's being sort of a jerk about it because he can tell "what's wrong" (both in terms of how bad she has it, but also the complications that will arise from who she has it bad for), but she can't tell what it is--until she raises her emotions to fight him about it--is friendship gold.

He's not always the nicest to her, and sometimes I felt that he was a bit too protective of a family that isn't his (although that has an eventual justificaiton), but he's her bedrock in many ways by being her sounding board, punching bag, and shoulder to cry on, all rolled into one.

Mixed-Up Investigation Agency, by the same screenwriter as Age of Youth and White Christmas, is probably my all-time favorite example of this, and I keep hoping it will become legally available some day. The first few episodes feel silly and cheaply made, but by the end it becomes something weird, unique, and wonderful.

I will say that some of the examples mentioned by the DB staff strike me as not so much "platonic" but as queer couples with a bit of "straight-washing" (School 2013, 25-21, cough, cough).

Oooh great prompt!! I'll go with the duo from Navillera Sim Deok-cheol and Lee Chae-rok. I just about died crying at that absolutely heart-touching ending scene. The trust and bond they developed between each other was unparalleled.

Sneaking in a second choice - the three MLs from Welcome to Waikiki - they're a hilarious comedic trio but also a wholesome found family.

There are so many, so it's difficult to say this is my actual, for real, die-on-this-hill favorite, but I'm going with Ga Mo-tak and Chu Mae-ok from The Uncanny Counter. Yes, they are part of a larger found family dynamic, but I think they count in their own right also. They are the older generation of Counters, both in seniority and age, and they function as confidants of each other in lots of different situations. I was sort of worried as I watched season 1 that the writer was going to introduce a love storyline between two of the counters, but they resisted that (I think) to the show's benefit. They are the beautiful, supportive parents of the found family, but in a platonic life partner sort of way, which just makes it more heartwarming.

Eun Ae and Jang Hyun (My Dearest)
Hwang Si-mok and Han Yeo-jin (Forest of Secrets)
Park Dong-hoon and Lee Ji-an (My Ahjussi)
King Sejong and Moo-hyul (Tree With Deep Root)

Kwak Dong-yeon and Kim Yoo-jung - Love In The Moonlight.
Kim Nam-hee and Nam Gyu-ri - You Are My Spring.
Hae-soo (IU) and the 13th prince(Nam Joo-hyuk) - Moon Lovers: Scarlet Heart Ryeo. I still can't understand the fate that befell the sweet 13th prince. Like why?
Lee Ji-an(IU) and Park Dong-hoon(Lee Sun-kyun) - My Mister.
Go Ah-in(Lee Bo-young) and Jung Jar-hoon(Lee Ki-woo) - Agency. It surprised me at how they didn't write a romance between this two. They clicked. Beyond clicking, they had a mutual respect and supported each other.

Was there a romance between the leads in On The Verge Of Insanity? If there isn't, I'm naming Choi Ban-seok(Jung Jae-young) and Dang Ja-young(Moon So-ri).
I don't know if this one counts. Jung Rosa(Kim Hae-sook) and Ju Jung-su(Kim Gap-soo) - Hospital Playlist.

A particular favorite that I desperately wished transcended into a romance...
Yeom Ki-jung(Lee El) and Park Jin-u(Kim Woo-hyung) - My Liberation Notes. I made them a pair in my own MLN ending. If Park Hae-young ain't making them a couple, I'm not hesitant to make a couple out of them.

The trio from Goblin, which led to some sweet permanent friendships between LDW & GY & YSJ. Their friendship and bickering was epic and beautiful.

This is right up my alley. My favourite has to be Lee rang and Yuri in tale of the nine tailed. Platonic perfection. *Chef's kiss. My heart still hurts when I think of them.

Honourable mentions:
1) Grim reaper and ji Eun tak from Goblin
2) Our two female leads in Mr. Sunshine.
3) Gong myungs and Han ji eun's characters in Be melodramatic. I am seriously shocked that they didn't end up together.
4) Go mun young and Sang tae in it's okay to not be okay
5) Cha hyun + Bae ta mi + Song ga kyung. *Chef's kiss
6) All the friendships in my roommate is a gumiho. Jae jun and hyeri's character as well as Kang Hanna + jang ki yong's.
7) Park bo young + Lee Soo hyuk in Doom at your service

I'm kind of sleepy so I can't remember all the characters names all now.
A good platonic friendship is 100 times better than a lackluster romance

Those were such great examples!
I have to go with the three at the center of Be Melodramatic. They were there for each other in every way, from hilarious to tragic. I’m glad to see some of the actrices getting other shows lately, because that show was tragically underrated.

For me, my all time favourite has to be "Woo to the Young to the Woo, Gu to the Gung to the rummy" - a truly beautiful friendship of two very different personalities from Extraordinary Attorney Woo. I also loved the respect and the friendship between Jung Meok Seo (her boss) and Woo Young Woo.

Shin PD and Writer Lee is the master in this craft. always deliver on one of the greatest platonic besties and overall BFF.

1) Reply series (all of them!)
- Eunji and Hoya in Reply 1997
-Go Ara and Son Ho Jun in Reply 1994
-Hyeri and Lee Dong Hwi in Reply 1988

2) Prison Playbook
-Je Hyuk and Joon ho

3) Hospital Playlist
-Ju Wan and Song Hwa (Piggy buddies!)

honorable mention:
-our favorite Bastard Friends, Nam Soon and Heung Soo!!
- Lawyer Shi Mok and Detective Yeo Jin

The friend groups in Reply 1988 were the first that came to mind for me. Not just the kids, but the older generation as well. They way they supported each other through thick and thin, good and bad times was just so lovely. Serious friendship goals there!

Law School showed that different people with different personalities can come together for the same goal. This is true to real life where your group of friends will not always share the same values, interests, and perspectives as you. You may be extra close with one or two of them but you will still hang out and be there for those that you are less close with.

I think My Mister shows the greatest variety of friendships (one of my favorite scenes is when the neighborhood crew springs into action after the fight with the loan shark), but for an individual I've got your back buddy, I like Oh Hae-young's long-time friend Hee-ran.

KBS’s OASIS. Jang Dong-yoon as gang leader Doo-hak. He was a loanshark with a heart of gold. I am excluding his relationships with the FL and other ML. He was great with all the guys in his gang and even the oldsters were crazy about him. OASIS is now my favorite JDY drama.

Just finished Sandglass which had the most beautiful and tragic friendship between the two male leads, so that's my choice.

So Mun and his friends during the 1st season of The Uncanny Counter is what came to mind when I saw the prompt. They were so close that they were pretty much family but maybe even better cause they could talk about anything without judgement.

Honorable mention: Reply 1997 squad. The girls, the guys, & everyone together. Take your pick haha

That is really a hard one. Just like kdramas has set the bar high for romantic relationships, it did the same for friendships. I would go with the one from prison playbook. For me the central relationship was the loyal-to-bone friendship between Je-hyuk and Joon-ho, it was heart-melting to see Je-hyuk greet Joon-ho that warmly when they ran into each other in a restaurant and Je-hyuk comment of "not being busy when it comes to Jun-ho@ speaks volumes of the deep bond those two share even though they haven't met in years.

the 2 friend groups in Crash Landing: the soldiers, and the village ladies who took care of their own 👍🏼

Too many to count. I’m glad that once again I’m reminded that men and women (or just anyone) can be friends.

Those that come to mind are

1. Yoo-rim and Hee-do (25 21)
2. Rosa and the head of the hospital (HP)
3. Song-hwa and Jun-hwan (HP)
4. (Teacher Kim and Nurse Oh)
5. Class President Ji Seung-wan and Moon Ji-ung (25 21)

The characters from Twenty five twenty one; diaper buddies Moon Jiung and Ji Seungwan. They were so close everyone was convinced they were a couple but they were proper sibling friends. Out of all the friendship group those two would definitely still be friends now just as their mothers will be too. It always surprised me how the mothers could remain friends without Seungwan’s mum calling Jiung’s mum out for emotionally abusing her son throughout his childhood. She needed therapy to get over her issues with his dad.

What is the first drama an the left? (On thumbnail I mean)
Isn't that park kyu young?

_ Platonic (love?) friendship boy + girl: Dong Shik and Bo Kyung in “Psychopath Diary”.

_ Platonic friendship boy + boy: Yeo Jun and Su Hyeo in “At a distance, spring is green”. (“Weak Hero Class 1” would be a good example too).

_ Platonic friendship girl + girl: Jung Hee and Hye Joo in “Girls Generation 1979”.

Pd:
Did the Chief Kim and Seo Yul have a platonic friendship? I don't know, but I hope they can be friends in the future.

A group of college friends that formed in the drama "At a Distance, Spring is Green".
Young women in their 20s from two seasons of "Age of Youth".
Friends in their 40s who knew each other since high school from the drama "The Others".

It is a pity that Zombie Detective stayed platonic but then it was one of the bestest Die-Hard-Ally dynamics of all times where they would have pulled the other out of tar and mud if need be. Also Bong Hee and Eun Hyuk in Suspicious Partner, I felt that for both it was a great outlet for frustration... mostly about the same guy for different reason. Common interest bonding.

Fight For My Way
I love friendships that are so strong they feel more like family than anything else.
Those four were a beautiful family, especially Ae Ra and Sol Hee with their mother-daughter dynamic.

More family-like friendships I love:
—Reply 88, Be Melo and Hospital Playlist (do I need to explain this? Hahaha)
—Just Between Lovers (Gang Doo and Sang Man. If family isn't someone that would give you their organs, Idk what is)
—Oh My Ghost (the restaurant's staff. They had such a love-hate relationship. That's real real family lol)
—Still 17 and IOTNBOKAY (both in my top ten found families. Moon Young x Sang Tae, and all the kids from Still 17. The high school kids and the adult kids).
—Mr Queen (Bong Hwan-ah and his girls. They would die for each, that's family)
—Reply 94 (Na Jung and Haitai were practically siblings. Super cute)
—Ho Gu's Love (in this case, one of the friends was really his family. Ho Gu and his sister were amazing).

I pick two: Da Li and Won Tak, and ML gumiho and his decades/ centuries? old gumiho lady friend (Jang Ki Yong and Kang Hanna, I think), from My Roomate is a Gumiho

One of the many things I love about Kdramas is how well they write community, whether that is family, neighbors or friendships.

So many favorites have already been mentioned here by others so I'll just add a few more:

The ladies of Sh**ting Stars have such great camaraderie and I love how well they support each other.
Baek Seung Soo and Lee Se Young's grudging co-worker relationship in Stove League that turns into one of admiration and support.
The high school boys of Still 17 - just adorable!
The Fight for My Way foursome, friends for life.
Kim Seul Gi is always great as the perennial best friend/sister but she has really good chemistry with Oh Yeon Seo in Love with Flaws. Their friendship was one of the few redeeming aspects of that series.
Jung Shi Hyun and Kim Hyun Soo's inspiring and heart breaking bromance in Heartless City.

I could probably name more, but we'd be here all day.

Under the assumption that the first one to come to mind is the 'correct' answer, my pick would be Ye-jin and Joon-mo in 'The Producers' (Gong Hyo-jin and Cha Tae-hyun). The last episode switch to romance doesn't count in my book. They're 99.9% childhood friends and you can't convince me otherwise. We never saw them do anything 'non-platonic', if I recall correctly.

The most heartbreaking one for me is Seo Hwi (Yang Se-Jong) and Seon-Ho (Woo Do-Hwan) in My Country: The New Age.

Is it just me or is this site crashing more than usual? Commenting and liking have been challenging

If I must pick just one, then I think I'd choose the 5 friends in Reply 1988.

Some other friend groups I would eagerly join: Because This Life is our First, Coffee Prince, Fight My Way, Woo Young Woo and Gu RaMi, and Weightlifting Fairy.

Whew 7th try, hope this posts

Many come to mind... But if I had to pick just one, I'll go with P.K. and Buja in Korean Odyssey because this spans throughout the entire plot line. While P.K. remains faithful to his character's personality from the actual book (aka someone who can't be trusted and would consider betraying Monkey at the first occasion), he is very protective of Bu-ja and he remains someone she can count on, even long after her body's been taken by an evil priestess. There is nothing to gain from this friendship from his perspective, and he's never wanted to gain anything from it. So, I've always liked the special bond he's got with her.

@mistyisles This is the first time U have been really intrigued about TWENTY FIVE TWENTY ONE. I just might start it soon...

@daebakgrits I loved the friendship between Joon-wan and Song-hwa so much that I wasn't really sad at Ik-Jun's lackluster romance.

@dramaddictally The friendship between Junho and Kang Hanna was the only thing I liked about JUST BETWEEN LOVERS.

I have to go with Dear My Friends.

It's ridiculous how much I love this show. How people can know each other so long and still be friends into the second generation is so amazing.

Of course, I look Hospital Playlist and Doctor Romantic, but Dear My Friends is it for me

Glitch 😉🤣🤣🤣
Just Gals being Pals!