The premise of this drama is pretty good. It really draws you in, but toward the end the time traveling story starts to get convoluted and straight up nonsensical. How come can Sol still be friends with Taesung in the future she doesn't meet Sunjae, when her following Sunjae around is what starts her friendship with him? There are other plotholes like this scattared through the story, I think the overuse of the time travel really harmed the story a bit. If the show ended earlier, it would've been better, in my opinion.

Also, I have to say, Sol was a bit annoying with her obssession with Sunjae at the start. I undertand the importance he has on her life, but she just barkes any sort of boundary of a normal fan. She's not even close to him, but she keeps acting extremely suspicious and like a total creep and just hopes for the best. She has no actual plan to help him and the only reason it goes right is because they are leads is a romance story, cause otherwise this is very problematic as she's literally a stalker and she'd probably get herself killed or arrasted in a few days. Besides, Sunjae doesn't have much depth. Despite having to give up on his dream and struggling with depression, we don't really dive into how he feels about these things or how they truelly affect him. Also, Sol and Sunjae's obssession with sacrificing themselves for the other doesn't fell warranted. Like, you barely know each other, please let's calm down a bit. I guess these types of over the top, melodramatic plots only really work in a more high fantasy or historical setting, not in this type of slice of life drama (despite having sci-fi elements).

Despite all of this, I have to say it gets better with time. If you can suspend your disbelief, Sol and Sunjae really become a cute couple and they really grow on you as the plot progresses. They have a lot of chemistry and Sunjae is peak loser behaviour (in a good way). They carry this drama on their back. Furthermore, the plot with the granny is touching, but a bit weird? Her Alzheimer is portrayed almost like a magical thing, but it's more comical than anything else. Taesung has a nice evolution throughout the drama, too.

If you're looking for a strong plot with deep characters, this is not for you. But if you can get past the more problematic aspects of this drama, you can find a very sweet and endearing story, with a lot of tension and drama, so if that's your thing, definitely go for it. It isn't anything new but it's very entertaining in this regard.