I started watching this randomly because I was bored and it turned out to be so good I completed it in three days.
The intro music made me happy.

Story
The story was interesting, I liked how he went back and forth between past and future. He is a really smart dude, he was always one step ahead of everyone. Yes, it's because he saw what will happen but he used that info in a smart way.
I thought he would be a cool cold guy but he turned out to be a funny nice guy.

Thing's I liked
- The romance, it was natural and cute and I couldn't get enough of it.
- Hee Jin teaching Boong Do how everything has something to do with kissing and him just accepting that.
- Their kisses and that one scene with spaghetti.
- Boong Do's smile.
- Cool fight scenes.
- Pretty much any scene with the two of them.

Thing's I didn't like
- Hee Jin's friend that's also her manager, she was annoying. She was a bad friend and a bad manager. I couldn't stand her.
- Dong Min, Hee Jin's ex, also super annoying. He is immature and an awful person. I couldn't stand him.
- Assassin's that were alive for way too long.

Overall, I had fun watching this and I would recommend it to anyone.