Unexpectedly Good Movie

I know this is apdapted from a book but I haven't read the book because of some reasons. I read a few negative reviews but still decided to watch to kill time. However, it was quite good since I watched with no expectation. It actually grew on me. The acting of supporting character is good. One the main characters did a good job considering he is an idol and this is his first main role. The acting of other main character is not as good as his partner. I wish they made the ending differently it was less heartbreaking. Overall, I will rewatch it.