Vivid Romance (2017)

Both are connected mini dramas in which one of the leads has low self esteem and undergoes a magical transformation.

Both are mini dramas with a lead lacking in self confidence or direction in life who undergoes a magical transformation.

Both are mini dramas with a lead lacking in self confidence or direction in life who undergoes a magical transformation.

Both stories are laid back and focuses on real-life issues without being over the top about it. Both male leads could be considered losers who tried to change
Both female leads are self centered but that flaw makes them real and easy to connect with emotionally

Both Male Leads take a pill (drug) that enhances their abilities...
Vivid Romance is about a guy who’s struggling with his police exam, and take a pill in a human drug testing place, has no side effects and become really smart and fit.
Bad papa is similar in the way that the male lead also take a human drug test and has no side effects from the pill but instead of becoming smart he come strong.