Songs you think would match "Last Dance"...

the closest one would be "a love like sad paintings (슬픈 그림 같은 사랑)" by lee sang-woo (1988)
or the old songs from the Reply series...
it should be overplayed 10000x for it to top last dance (chances are almost zero lol)

as you can see by my display name i'm very against last dance competitors dnjskxnasxjkz

Last Dance by Wu Bai is a blues-rock I spose?  That genre wasn't (and still isn't) popular in S. Korea, so finding something similar will be a needle in the haystack. Last Dance is also extra special, since the lyrics speak of many concepts/ big ideas of the story (i.e. separation, longing, dreaming, wanting to see your special one,  etc.) I cannot help but wonder if the song was the inspiration for writing the story in the first place, since it was a WIP for about a decade and half (yes, perfected over 15 years or so!)
I wouldn't be surprised the writer was actually inspired by Last Dance, like Tapestry (2020) was inspired by Ito- Miyuki Nakajima & First Love Hatsukoi (2022) by Utada Hikaru's titular songs! :D

25-21 is set in similar time-period (i.e. Late 90's- early 2000's) so the OSTs and sound-design used there could give us a good idea what piece of music might be used in place of Last Dance. Or, the second best bet is to create a fictional song & pretend it was released around 1996? ? Meanwhile, I'll continue to listen to 90's Rockstars from Korea and see if something catches my attention! 

 David Sun:

it should be the first song of either A or B side of cassette, because cassette player can not pick a song randomly.

Valid point! Me thinks they'll compose an original track, and record it over a blank cassette? A make-believe song from the 90's.
They could even write Korean Lyrics against the same tune, to pay homage?
Also, who says it has to be a Korean artist? Snowdrop had One-way Ticket, Youth of May had Annie's Song... :') Though, the only problem is the artist has to perform a concert in Korea, so a foreign artist is not likely!

I don't know of any Korean song that could be used to the same effect as Wu Bai's Last Dance. The Lee Sang-Woo song recommended above is an okay pick, but I would be bored of it after hearing it 3 times. 

My stupid recommendation is to just give up trying to go for the same feel & just use Turbo's Black Cat,  its various remixes & later KJK performances of that song to keep it as fresh & funny as possible. (plus there is the insane dance potential)

Omg. Tough question. Considering the year, i tried some ballad rock because i thought it was common in korea in late 90s-early 00s. I did a quick browse and couldn't find any song that matched the vibe. Most of the songs i tried listening are too mellow xD

 Chibi:

Bingo! And that's because 90's Korea was listening to mellow Ballads. Even their 'Rock' was either Punk or Alternative, whereas Wu Bai's music is Blues Rock. You can't get those RnB, slightly jazzy, slightly folks-y vibes from the Korean music scene back then... ?

To be fair, mellow ballads are a hundred times better than what they are listening to now. Kpop  today has barely any value as a genre of music, it's all about pretty people dancing. (with few famous exceptions)

 t i a r a:

Does it have to be song from the 90's?

Absolutely not!! It just has to satisfy two criteria.... 1. The song has to be the first song released on either the A or B side of the cassette (as mentioned by David Sun above)... and 2. The artist still has to be musically relevant enough to have live performances in 2022, across Korea (if not internationally).
If it's hard to find someone from the 90's satisfying criteria 2, it's gonna be harder looking for it during the 80's!!!

Blues rock is relevant even today I believe... Ballads, not so much? Although they are making a comeback, and the revival movement has an ardent fan-base among the Koreans!