Scenario one recommendation:
Ugly alert - very loong family drama, all 30 minutes duration of its 133 episode count. But the relation between the leads is very very very solid from the start. They got together about ep40. People get intimidated because of the episode count, but dont let that intimidate you, this drama is a must watch.
Glorious Days - very awesome romanance between the two leads that starts very early in the story
Shut up flower boy band - they became attracted with each other verybearly on. And they became a couple quite unexpectedly fast.
Scenario two, recommendation:
Healer - does it count of he is jealous against himself aka his other alter ego? cuase that was totally one of the best petty jealous scenes ever
Greatest Love - cha seungwon in his epic petty temper jealous tantrum was awesome. Both main characters in the drama are celebs, and she went on dates for a show like 'we got married' does it count as the BOF style dating?
Fated to love you - taiwan version. Ethan Ruan is the funniest lying conniving jealous guy ever.