In the end, Jae Eon's development fell short for me because of that.
It rained, nevertheless, we proceeded on our journey; we did not the less proceed on our journey; we proceeded in opposition to the rain, without regarding it, or without being prevented.
She finally realized he was being sincere, which was what she was struggling with this whole time.
.
He relinquished his 'playboy' affectations while she embraced the fun of having a pretty bed partner to play with, long term consequences be damned.
He's notoriously hard to get and has seemingly no real interest in anyone else, although this is disguised by his flirtatious nature.