The male lead are both CEO of an IT company and both ocd yet gentle and caring to their employee. The female heroine are the same in a way of pursuing the boss. Both dramas are funny, romantic with good amount of drama.

same lead actor ~ Sung Joon and he makes the ladies swoon
same feel of romance and comedy

same feel of comedy and directing style
both manga based
high school rom-com
both movies have the female lead really love or pursue the male lead

same male lead - Kento Yamazaki ~ high school rom-com
L heart DK based on manga, two high school students lived in the same apartment complex and turn of events male and female lead will share the same apartment room.

There is no ghost but the same setting of culinary and food and romance. Great drama!

Love On A Diet has both male and female leads to be overweight and they both lost weight for the sake of love. Great movie! Andy Lau and Sammi Cheng!

same concept - older woman younger man but in Oh My Lady, both the male and female leads are single parents. good rom-com and did I mention SuJu hottie Choi Siwon is male lead :)

It seems most Johnny's rite of passage ~ older woman younger man drama - this time with Jun Matsumoto :)

Shinohara Ryoko once romanced ex-Johnny's hottie Jin Akanishi in this romantic comedy

hottie idol Kamenashi Kazuya falls in love with a beautiful older woman

Same genre ~ younger man falls in love with an older woman ~ romantic comedy