It’s just not fucking okay to make advances on an ex who: not only broke off the relationship, but has consistently rejected your prodding, asking leading questions, and inconsiderate confessions.
I don’t think Amane recognizes what she’s doing as harassment, but intention doesn’t absolve her of responsibility. Especially after Nene agreed to stay friends because she knew it would soften the blow for Amane. She’s just been exploiting that trust selfishly.
I hope Amane finds a healthier relationship than what she’s immersed in, yes, but right now she’s doing all of the hanging-on.