Thank @Dundun123 for your kind words.
and @Fortes, this is one of my favourite chapters so far for this series because of Koharu's emotions and thoughts. Gosh...
The problem was when she was cornered into marrying because of a debt her parents generated.
Thruthfully I skipped the whole middle ground, because the beginning was just too uncomfortable, the dynamics already messed up enough that a fourth person woudn't help. Decided to read the end just to see how it developped.
How is leaving a relationship you're not happy in means running away?? It means she's chasing her own happiness! I think the author has some screw loose in the head.