Mitsuru picking the "romantic" spot wasn't thought out very well, it reminded Haruka of her sister after all... it was the last time she gone out with her when she wasn't scorched.
He might fucked up, but quickly recovered and actually made Haruka feel bit less depressed. He's smooth and that kiss moment was actually pretty sweet.
Oh I dunno, maybe being the ringleader in bullying that made other kids kill her parents and crippling her sister
Wait, what?!?
At first Taeko and Haruka were friendly to each other (ch12.2 extra) but she got angry on her when she got involved with Mitsuru and started to bully her.
Rumi has unrequited love to Taeko, but she hates her and bullies her.
Taeko liking Haruka or has unrequited love, but that doesn't explain her bullying.
This is so confusing, why was Taeko bullying Haruka if she didn't "stole" Mitsuru from her, she doesn't even like him.