
Who hurt you? A child shouldn't be blamed just for being born. If your theory is true, you shouldn't hate her just cause the mc's father had an affair.

Hate the father sure, but the girl did nothing

The mother was cruel to rent out the place to a woman who may well be the half-sister. It's a reminder of being abandoned for someone else.
And I'm with the OP. I'd burn the fucking place down. BEcause if that is the half-sister, she should understand how VERY painful this has to be for Chiyoko. (I suppose there's a twist here.)
I think if Chiyoko can get through this and be happy, yay. But right now, I'm so angry at the Father AND the Mother for how they treated Chiyoko. Both of them neglected that girl. And that's evil.
Yeah, I'd have burned that place down.
But that's just my emotional response. The best thing is that they cooperate and Chiyokos both make choco and be happy.

I know that's the best course of action a well, but I tend to fly off the handle for characters I either really like or find relatable. This one would be the later since I could easily see myself being depressed if my father suddenly disappeared, but I would wish for his happiness and that he would at least come and take me away from my mom.

I feel you. I think if the New Chiyoko wasn't coming across as so damn neener/neener smug: "I know what you don't know. YOu never listened." I mean, she doesn't even KNOW this person, and is already saying these things in a superior stance.
I assume this Chiyoko had conversations with the mother (and mothers will tell others what they won't tell children). But still, to basically say it's Chiyoko's faultl, as if adults don't carry the blame when they hurt kids, it's terrible. Terrible.
I really don't like the game this New Chiyoko is playing. It is like emotional torture.
I get the feeling he left for another woman and that girl is supposed to be her sister if so, kick her out and burn the place down to ash! (╬ ̄皿 ̄)凸