She will need a change of scenery to be able to get out of that passionate affair... for ex study abroad unless Jae Won does move abroad as suggested.
She is NOT in love with her childhood friend ... but with Son Kang. And yes she needs time alone for a while, far also from those friends she has now.
As long as she sees him she won't be able to get him out of "under her skin" which is how I perceive she feels for him. That's why she succumbs to temptation even when she decided to stop it ...
Son Kang might grow out of his "butterfly" period eventually .... but at his own rhythm. They might be good for each other later in life...
One thing is sure this kind of attraction - passion is rare. They have much in common as artists .... let's not forget they both study art and with it comes creativity - often at a price - and "special" temperaments.
Anyway great unconventional show!