Recommendations

There are some pretty strong parallels between the two main leads in each series plot-wise and both titles involve the music industry as well.

both dramas are similar in the sense that both the mains are going to a music school and play some sort of instrument.

Both are about marriage and pleasant to watch.
In 'Marry him if you dare' exist an love triangle as in drama Marriage not Dating.

In both dramas the female lead is a celebrity who has her own career standing on the edge, while the male lead is an alien who has to live a limited time on the Earth and they both fall in love.

Two men, living their lives closely following the rules, and chaos they create.

Both really cute, rom/com dramas. The main actor is hot & both have great chemistry. Must watch, you'll love it!

Films quite similar to each other, and the creator of the two films is the same person.

Both revenge dramas that include romance. ToW is a lot longer, but I don't feel like it's dragged (start from episode 30 if you aren't patient)

Hospital ER backdrop in EMERGENCY COUPLE. Mental Hospital backdrop in "IT'S OKAY, THAT'S LOVE." In both, the couples start out with a rocky relationship. In both, the romantic history between some of the characters adds to the interest of how characters relate during the drama. It's Okay, That's Love seems to be More Serious Drama with Comedy and Emergency Couple seems to be more Comedy with serious.. Both succeed at being respectful of the the serious material, while still delivering some fun comedic scenes.

From what I can tell It's from the same era, and the story/characters are somewhat similar to each other. Dororo might have a slight different genre, tipping more over to fantasy and may seem a bit ridicolus at times, but still has a great cast.

These are both office dramas loaded with great humor and good acting.

Both dramas have similar theme about young people trying to survive in music industry. And Ji Hyun Woo has the main role in both.

Same main Leads, the Chemistry between them is of the charts in any common roles they share, no need to say that Stairway to Heaven is the utmost classic tragedy, However carries the same sweetness in the love story as Temptation. Enjoy watching the Younger version of the leads in Stairway to Heaven and the adult version and chemistry of their scenes in Temptation..

If you liked Heartstrings try Trot Lovers, they both feature a pop singer male lead paired with a traditional music girl and they both have really good ost musical scores that are catchy and will get you wanting to sing along with them. They also both have really good and quirky side character relationships.

They told the same history. You can choose the new version or the old one