The female leads in both the dramas are weirdos .

The male leads of the both the dramas are prosecutors . They act tough in front of everyone but are actually dorks .

The male & female leads of both the dramas meet each other through a fate .

Both have a lots of comedy but deal with serious cases at the same time .

~Both the dramas are of Romantic-Comedy & Thriller genre .
~Both the dramas have a very strong , sassy & adorable female leads .
~Both the dramas deal with serious crimes & criminals .
~Both the dramas have very adorable male leads who can melt your hearts .

The genres of both the dramas are same :
- Sci-fi
-Suspense
-Thriller
-Crime
Though the plots of both the dramas are totally different .
But while Circle has a Human B system , Simple Man has a Devil software which influences people's lives .