The Greatest Love (2011)

Gu Ae Jung was once the most popular member of the girl band, ‘The National Treasure Girls’. When the band broke up ten years ago, she received the bulk of the blame. Despite her warm personality, her career has suffered ever since and now she vies for air-time as a B-list celebrity on variety shows in order to earn an income.

Dokko Jin is a top movie star at the height of his career and his next goal is to break into Hollywood and gain recognition as an international and global actor. However, his attempts to get his first international breakthrough gets scuppered due to a series of unfortunate encounters with Gu Ae Jung. Despite his initial dislike, Dokko Jin surprisingly finds his heart beating a little quicker from their encounters. Is this the beginning of what could be his greatest love?

This might be far-fecthed similarity but both have characters working in the entertainment industry and I see something similar in Dokko Jin and Do Hyun's characters.

Gong Hyo Jin. i've watched two dramas both and i absolutely love her acting and her chemistry with the actors are undeniable ! she's an amazing actress, no doubt. And there are a lot of love scenes in both dramas.

-Both female characters lose their popularity in the industry due to certain accidents and had to do all sort of things to stand again.
-Both male characters suffer from a sort of disorder/bad health condition.

These two drama:
—deal with the entertainment industry
—have eccentric accomplished male leads who deal with certain health conditions
—the female leads have both a notorious reputation
—the couple goes through various difficulties to be together

Both are about pop stars who have flopped out of the industry and are living their lives.

Both Main Male Roles Have Same Personality,and they give me the same 'feeling'(I love their moustache!xD)

Male Chases Female First
Love Triangle
Misunderstanding
Rich Man/Poor Woman
Scandal
Hardworking Female Lead

High school graduate Gong Xi gives up her chances for university in order to support her childhood friend and romantic goal, Bu Po Shang, in his pop idol career. Upon arriving in Taipei, Gong Xi starts working on multiple jobs in order to support Bu Po Shang, whose popularity quickly rises, eventually becoming one of the top idols in Taiwan. One day, Gong Xi catches Bu Po Shang flirting with his manager, and learns that he only used her so she can help him with his living expenses. Heart-broken and betrayed, Gong Xi vows to get revenge by becoming a bigger star than him. Gong Xi auditions for L.M.E., Bu Po Shang's rival talent agency, and joins L.M.E.'s new-found department "Love Me". At L.M.E., Gong Xi meets famous actor Dun Helian, who eventually falls in love with her. ~~ Adapted from the manga “Skip Beat!” by Nakamura Yoshiki

The pairs have a similar dynamic, and there are a lot of similarities among the male leads..... plus the potatoes!

both dramas are about celebrity life and both the male leads are conceited. ;)

Both center on a relationship that is severely tried by public status and the need to keep it on the down-low, especially in the early stages. Both male leads are older and zany, with a touch of cool; they also each undergo a physical style change which alters their appearance drastically. Both female leads are tough yet inwardly vulnerable, reluctant, and have complicated family lives. There are hilarious assistants accompanying the male lead and somewhat pitiable, yet occasionally nasty second leads. Mix in cruel Netizens for added similarity.