To be fair, I've watched Hello Monster a long time ago and I don't have any memories of the series at all. I remember some scenes (especially the fantastic acting of Do Kyungsoo) but I don't quite remember the rest of the series so I couldn't really compare with this one (except the beginning of the plot). And maybe because it was a long time ago but I remember liking the Korean series.

This Thai version... not so much.

The actors are good. The plot is well written. But there is one big problem for me... the female lead.
She was insufferable from the start and, from episode 4 or 5, I couldn't see her on the screen anymore and I had to skip all of her scenes (especially the ones with the male lead). I re-read my comment on the Hello Monster series and I was already saying at that time that I didn't quite like the romance. But I don't remember hating it that much! That Thai version seemed to have worsened the female character. I mean... she is a cop but she's scared on a crime scene... She also is and admits to be a criminal herself because she's a stalker but the male lead doesn't seem to be put off by this news... She says to Pathomkarn that she hated Tanwa at first which is a total lie. She never hated him and, even though, she doubted his innocence in the first few episodes, she never disliked him, on the contrary. She also prefers that her attacker run free just for her to stay in Tanwa's home. Well... I can go on and on with her...

Also, she is the reason I hate the ending. Because, of course, we can't have an ending with the two brothers being happy together...

So, I may be unfair to the series because of one character but, sometimes, one character can spoil an entire series...