A college romance that ticks all the boxes plus some. It's simple but so good in portraying mental health and healing.
I'd rate the first half 8/10 and the second half 9/10, therefore overall it's an 8.5/10.

All actors gave a very solid performance, I've been enjoying the works of both leads for a while and given the right script both of them can truly shine. For the first half of the drama I'd say they were a bit underutilized and it's probably not the biggest challenge to take on a college romcom drama script but their natural acting gave the drama a sense of realness.

It starts out typical but enjoyable. We see common tropes such as childhood connection, nice extroverted FL, an introverted genius, somewhat distant ML and other all to familiar drama accessories.
But what sets this drama apart is it's portrayal of how the environment you grew up in affects your day-to-day life.

If you happen to be a child of divorce, then this one will probably hit you in the feels (as it did with me). Let me give you a quote as an example.
"When I was little, my mom and dad used to dote on me.
Then one day, they parted ways without telling me the reason
and suddenly I became a person without a home.
I really really hate holidays.
I hate summer and winter vacations even more.
Because I don’t know where to go.
Wherever I go it seems like it’s someone else’s home.
I feel like a piece of luggage that can easily be thrown out at any minute."

Other mental health issues and topics related to childhood trauma(no physical abuse) were:
- abandonment issues + loneliness
- C-PTSD(probably) and anxiety

Without spoiling too much I want to say the leading couple was very supportive and had great communication in the second half and in light of the mental health issues caused by the MLs childhood I have to say I really enjoyed the scriptwriting. Not all is forgiven and finally a character actually speaks out about how the environment they grew up in harmed them. Episode 17-24 were great, with 21 being my absolute favorite.

Another thing that ties this drama together is it's choice of music. Nostalgic piano and emotional english songs like "In Two" and "Feelings Find A Home" made it feel much deeper, than say your average up-beat cdrama BGM.

Lastly, the not so good:
- the whole "proving with science what falling in love is" was picked up and dropped every couple episodes. It clearly wasn't the highest priority, the main plot was the childhood connection, hurt and how they re-connect. Once it was established what their past was, they no longer needed that aspect of science. It was fine nonetheless but it didn't stick to it's original plot (or the japanese manga) but as I said above I enjoyed the second half more anyway.

The massive no-go:
The lab monkey. Honestly it's 2023 and there was ZERO reason to have an actual monkey in a cage, visibly distressed and not criticizing it at all. This infuriated me soooo much. All just for "funny" scenes to make the FL seem embarrassed in front of ML.
At one point (ep5-7) you could see that off-camera someone blew air at the monkey (probably a leaf blower or something) to make it go into a cage. This was not part of the actual scene but it was clearly visible on the fur of the animal and showed how the animal was treated by the handler.
Same goes for the lab rats that were yanked around by their tale.
These two incidents did not happen ever again after those episodes but it also makes me rate it lower.

VERDICT:
All in all it was simple but had depth later on with great quotes, emphasis on mental health/healing and I loved the ending, it was done so beautifully - it's been a while since I was so satisfied with a drama ending. It also had a nice second leading couple (the guy lowkey looked like straight out of a high school kdrama, lol)