I'll keep this sort of short and simple:

1. The concept of the love alarm makes zero sense unless people are entering their info and crushes in the database to begin with. What the hell is with the linking their heart thing?? There was potential but the writing was lame.

2. This just romanticizes stalking. Both Hye Yeong and Sun Oh are actually creeps.

3. Sun Oh is a terrible friend but Hye Yeong is annoyingly passive.

4. It made no sense that 3 guys were after Jo Jo (including her original bf). There was nothing that stood out about her character. There was no chemistry between any of them either. Additionally, Hye Yeong and Sun Oh didn't know anything about her for them to be into her like that. Especially Sun Oh, who seemed like he just wanted to get her before his friend could. They just followed her around and stared at her from afar like weirdos.

5. The characters are all unlikeable, unrelatable, and boring.

I decided to call it quits after a few episodes. I don't care about any of these people or the story for that matter. Since I didn't watch all of it, you don't have to take my review seriously. It could get better but these were my thoughts from the beginning. The foundation wasn't strong enough for me to continue.