I have watched this series 4 times. It is quite diverse with Taiwanese (second ML) and Korean (ML) actors
The story line is good. I laughed and cried each time I watched it.

Korean male actors in chinese dramas.

The acting is brilliant. I think the chinese male actors can learn some acting skills from the Korean actors. Their facial and body gestures communicates without words. The way they express their emotions, its really inviting.

Second ML and FL, their acting was really good.
The acting of the villian was not good in the first episodes, but improved.

The devil is in the details

The ML pays closed attention to the FL's every action, hence, he informs the doctor that she often falls asleep and ask for a full medical examination.
Furthermore, after doing research of her illness, he sets "share location" on her phone to find her if she has an attack.
I love his attentiveness.

The FL, she does not exaggerate her tomboy role. While she is naive, innocent, humble, strong willed and has a sense of justice - she lacks self confidence. She is really very cute.

In my opinion and experience as a "Tomboy"- her mother sees her as a tomboy, therefore, giving her a tongue - lashing instead of comfort because she is accustomed to doing so. However, she is aware that her daughter prefer to silently cry by herself.

The rest of the acting by the other actors - ?