Recommandations

Marriage, or the benefits of marriage, is the main goal for the plot of each drama; granted, it's approached by the leads in different ways. Both dramas also contain quirky humor, fantastic supporting characters (and family members), and a sweetly developed romance (though frustrating at times).

These two slice-of-life dramas take place in extraordinary situations, and have a similar tone in both the comedy, romance, and character growth. Both dramas' female and male leads are similar in how the female lead seeks her place in the world (particularly through a job) and the male lead often keeps to himself but opens up over time. Hoshino Gen (Hiramasa Tsuzaki in Nigeru) also sings the theme song for both shows, a similarity that coincides with the overall vibe of the shows.

They're both slice-of-life in a way, but contain quirky humor and relationships that go from passive love/hate to the characters being on the verge of marriage. The main characters also tend to go outside of their comfort zone in order to grow as people or accomplish tasks.

Sweet drama
Leads love each other very much
Although YB has a lot more complications but idk why I just thought of YB while watching Love o2o
Btw it's hilarious throughout the series

It's the first film version of the InK and another one to add to the 'stable'. All the characters are the same and the story follows the original manga/anime; much as this drama did.

It's the first film version of the Itazura na Kiss (another two to come - campus and proposal) and another one to add to the ever increasing 'stable'.

A bittersweet love story with an ailing lead actress that leaves you wishing that their lives would have been more fortunate.

Both dramas have a similar setting/Period they play in. Both female leads aren't push over and seek revenge on the country that destroyed theirs and the enemy that appearantly killed their loved once but evetually both female leads fall in love with the royal of the enemy country and become concubines now dealing with the jealousy and intrigues of the Harem/court.

Both have similar elements, with a rogue tabloid (funded by a gangster boss) along with a driven female law enforcement character going up against a large paper (with a corrupt boss) to uncover a larger conspiracy; both are about how media shapes pubic opinion and the moral dilemmas that go with reporting. (But Hero is way better written/acted, and for being made 8 years earlier, way less cliche!)

The crime part of the story in W reminded me of The Legend Of The Blue Sea
Both are Love story with cute and sad parts as well
(and with their own kind of humour)

Both are about washed up musicians who now host a radio show...when the daughter(s) they never knew they had show up to live with them.

Similar plot line with a career woman with fertility issues and multiple suitors

Setting: historical and fantasy
Both leads love each other very much( would die for their lovers)
Interesting side characters
Female antagonist keeps trying to steal the male lead(same actress)

They both have Cecilia liu the amazing female lead
Setting is historical
Time travel n Cecilia is trying to help her lover
Plus they're both amazing dramas

Both have Lee Jong Suk starting in them. Both are about law. Both are made by the same writer.