-In both, male leads are doctors.
-They are hard to impress and hardly get involved in any romance.
-In both, female leads are the first to take initiative and seduce or impress the male leads.
-In both, female leads are public figures.
-They are bold, smart, beautiful and kinda fool when it comes to love.
-Male leads knows how to cook, whereas female leads cannot cook.

-Both dramas are based on the theme of investment.
-The episodes are 36 in love is sweet, whereas episodes are 40 in you complete me.
-The titles are named on the basis of romantic genre but the dramas are not ONLY about cliche romance.
-Workplace romance.
-Time leap/ Time jump would also be shown.

-In both, male lead had an accident for the succession for a conglomerate.
-After accident, male lead gets picked up by female lead without her knowing of his identity.
-The rich male lead lives a poor life with a poor, hard-working female lead and causes her troubles everyday.
-Most importantly, male lead suffers with amnesia so he forgets about himself and about his identity.
-While living together and even having different background, male and female lead falls in love with each other.

-Both consists deities from another realm.
-In both, deities come to the female lead and falls in love with them.
-In both, female lead are miserable and suffers with misfortune.

The major difference firstly I'm gonna mention is ; that way back into love jumps from high school into adulthood whereas first romance simply jumps from high school to university life, but the basic similarity is that in both the dramas, both leads were each others first love which they couldn't able to declare or confess due to certain misunderstandings and circumstances but later at a different stage of life they met again, realized their feelings and their love was able to bloom.

In both, leads used to know each other when they were in high school.
Leads got separated after high school and then met again as adults and in same workplace.
The romance wasn't able to take place in high school but it blooms in the same workplace between the leads.
Indeed, female lead works under the male lead and surely these bossy male leads are tsundere.

It is a college campus story between the leads.
There might be a love square between the 4 characters of the drama.
The chemistry is undeniably strong.
The female lead is cute, quirky and cheerful
The male lead is subtle, shy and kinda quiet.