Both dramas have main leads that experienced a traumatic event in childhood that led to unforgettable experiences together. (Also both childhood ML is Na De Reum :)). Both dramas have an underlying angst and PTSD -like symptoms among the main characters. Both have a main couple that works through their relationship in a healthy way and support each other. Both dramas have a SML / supportive colleague that creates a trio that takes on the world together ! :) no fantasy element in Radio Romance but the overall mood is similar.

Both dramas have a ML who uses deception and manipulation and stalking etc to chase after his one true love with all the best intentions.

feels very much like splash splash love similar vibe and timetravel of student and student sharing ideas with monarch who is someone that thinks differently , far ahead of his time , instant connection

Both have childhood connections with tragic pasts and siblings dying. Both have a similar looks and feel with a balance of heart stomping loss and grief and light comic moments. Familiar palace characters In both.

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.

Both these dramas have a calm feel and a romance that is gentle in nature . There is a natural rhythm that both couples seem to own for themselves in the midst of everything else going on around them. The ML in both dramas are scientists and the FL in both dramas are in the entertainment industry. Both dramas have moments where the highlights the difference in their professions but shows that they are both excellent in their own fields. The FL in both these dramas take the first stop to initiate the relationship and the ML is thoughtful before responding but once he responds there is no wavering.

Same actress as FL. Feels similar as she feels a strong pull to protect the ML due to his visual impairment. He is quiet and attracted to her personality as it is opposite to his. The relationship is building similarly.

MLmasked hero and dandy nobleman identities
FL in triangle with both identities
Fighting justice together
FL cohabitation status temporary will have to leave
Light whimsical tone to drama

MLmasked hero and dandy nobleman identities
FL in triangle with both identities
Fighting justice together
FL cohabitation status temporary will have to leave
Light whimsical tone to drama

FL Is crazy about ML
ML is popular and smart and treats FL as if he does not like her, although he knows and accepts her adoration
They live close to each other in both settings but keep it secret
Supporting character (SL) similar in actions and attitude.

Both these dramas show the FL and ML with chance meeting and not knowing each other's real identity - which is funny since the FL treats the royal ML like a commoner - of course this helps them develop the relationship
Both dramas, the bodyguard is an unwitting ally
FL serves at side of ML in an effort for ML to keep them around - even though it is not looked on as okay by others
Both, Bickering-type dynamic and both FL always getting in scrapes with the ML saving
Bodyguard is the coolest character in both dramas
Jinyan is MUCH lighter and not as well made
If you like Jin Yan, Moonlight is a much better interpretation of a similar storyline

transported to a different time/dimension and finding romance and a way to return to own reality
wealthy ML , dyanamic FL