Fl being absolutely oblivious to their and other people’s feelings. I don’t know about others but isn’t that like the easiest thing ever, knowing you like someone and especially that you’re falling in love. Doesn’t the signs become obvious to them. Also someone being so attentive to you even sometimes kiss you, I think that’s enough to tell this person likes you. But drama leads (especially the females) will deny it till the very end when he spells it out and puts himself in trouble for her to prove his love.
The female lead must twist her ankle at some point or get drunk beyond her limits to be piggybacked.