I feel the same about Haruka and Chihaya, but I manage to love and hate Chihaya at the same time!
Such a thing never happened with me before, I could only EITHER like or dislike characters.
And what about the song? Did it make you like Chihaya at least a bit more?
I either love a character, hate them, or they're just kinda...there.

I LOVED Makoto, Karasu, Joseph, Iori, and Riffa.
I HATED Saku Hibiki and Del Donna. And to a lesser extent, Chihaya and Yukiho after the former went insane and the latter
betrayed Mondenkind.
I DIDN'T CARE about the twins, Haruka, Ritsuko, and pretty much everyone else.
Except I really liked Hotaru and Chikako. And Naraba, Sorewa, and Naze.
And I was pretty mad at Azusa after
she just turned around and fired Makoto. I forgave her
right before she died.And about the song...frankly, no, not really. As beautiful as Kaori Shimizu's voice is, Chihaya's character and attitude was still just downright rotten in the later part of the series. It made me really furious at her, and I often found myself screaming at her. I understand her, but that doesn't mean I could necessarily forgive her for everything she did.