I read the webtoon before watching the drama and found the story, plot and characters to be interesting, make sense and lovable. The drama on the hand...not so much.
There are one too many changes that for me fell flat and ruined the story. Not to give too much away but Bo-gyeom's change in backstory and character made me dislike him more than Seo-won's bully. Also the actor who plays Seo-won didn't have much of a range in expressions in showing his affection or happiness towards his crush Hae-na. He had a emotionless cold stare most of the time whenever he felt sad, angry, frustrated or happy. Then there's Hae-na whose character came across as more diminished than spritly, fun or having gusto.
Overall it was a "meh" watch. Wouldn't watch it again or recommend it as one to watch put on a watchlist. Which is a shame because "See You In My 19th Life" is a webtoon written by the same author of "It's A Good Day To Be A Dog" and that drama is better than this one.