This romantic setting has been seen in plenty of K-dramas already.
Romantic Korean dramas are undoubtedly fun and iconic, but they can also be cliché-ridden. So it’s normal for the same tropes and settings to be found in different series. A major cliché romantic setting that is often associated with important milestones of K-drama couples is watching the fireworks together. Many famous dramas such as The Master’s Sun, Weightlifting Fairy Kim Bok Joo, Hometown Cha Cha Cha, What’s Wrong with Secretary Kim? or most recently, Business Proposal all include scenes of the two leads sharing sweet and heart-fluttering moments under the fireworks. It may be overused, but it still succeeds in making audiences swoon.