I've watched a lot of korean and chinese dramas so believe you me, I am familiar with cringe media but this is on another level. If you're ever considering watching it, don't. Don't waste a precious 5 hours of your life watching this ridiculously terrible thing.
I watched worse. It's not a good program, but I had fun with it (I recommend Prom Pact if you want something more similar to To All the Boys I've Loved Before)
