Both these dramas tell the story of the relationship between the ML and the FL in online and real life. It is the ML who discovers their online friendships first after making issues for the FL offline and then try to make up for it.
Similarities:
* Both MLs are "smart" and end up rejecting FLs school paper that prohibits her from graduating.
* I think both MLs end up falling harder in the end
* No ugly or messy love triangles.
Differences:
* In "Fall in Love With a Scientist" the ML has had a crush on the FL for a long time, so he falls first and takes the initiative in the relationship. In "Perfect and Casual" the FL falls first and later the ML realizes he likes her.
* Perfect and Casual has a contract relationship, and they live together. FILWAS does not have that trope.
* Both MLs are "smart" and end up rejecting FLs school paper that prohibits her from graduating.
* I think both MLs end up falling harder in the end
* No ugly or messy love triangles.
Differences:
* In "Fall in Love With a Scientist" the ML has had a crush on the FL for a long time, so he falls first and takes the initiative in the relationship. In "Perfect and Casual" the FL falls first and later the ML realizes he likes her.
* Perfect and Casual has a contract relationship, and they live together. FILWAS does not have that trope.
Same cute adorable socially clueless character as ML as well as actor in the role. Both have an illness that adds angsty dimensions. Both dramas have the FL and ML working together. FL is even a cleaner in both dramas at some point in time. Most importantly both dramas have a similar look and feel. Colour palettes and light romance sprinkled with bit is external trials.