And now after confessing painfully to Anna, Mari immediately moves to Mattsun? I think the author is muddling things up too much - with the quick switch it’s unclear whether her feelings for Anna are truly romantic or it’s more like a she was her first and only true friend, so she held her as precious and was jealous of her attention.
I’m also getting tired of Anna. She isn’t responsible for other people’s feelings, and it’s very annoying that she is struggling more with not returning their feelings than they are with being rejected. Yes, rejecting someone (especially a close friend) is sometimes sad, but she’s just wallowing in guilt even as they move on. It would make sense if they begged her to change her mind, or were avoiding her or acting different, but instead they don’t even have serious expectations that she’ll return their feelings
That goodness for Tsuyoshi and Yukirin, providing a stable, mature couple.