Damn, just damn

She was in the perverse position of having been burned badly by the same mistake before, but still couldn't help doing it again.

if this was SMT

Kazusa is the Chaos route.
Setsuna is the Law route
Koharu is the Neutral / Human route

Guess it's their very existence some people despise. Yui in Oregairu is an interesting predicament because the love triangle is acknowledged by all in it and there's a push to address it, rather than the usual ignorance, politicking and characters taking dives.
This desu, it was legit. He was digging Kazusa but not as if he didn't dig Setsuna too, or else he wouldn't have accepted her. She went for broke but reality didn't bend in her favor; Haruki didn't stand by his decision, Kazusa couldn't bear it.