Sublime mixture of wacky romantic comedy and serious character study, rooted in real emotion, with a mesmeric lead performance by Seo Hyun-jin. The music's great and will stick in your head, the characters memorable and wonderfully realized by a universally good cast, and the show's writing and pacing are on point. The way the varying moods and tones are almost effortlessly handled simply could not have been done in a Western show.
It's a show you'll want to re-watch almost immediately after you've finished it, to catch all the little nuances you might have missed upon a first, chaotic binge, and also to luxuriate in all the little details and moments, all put in to give pleasure to the viewer.