Its almost weirder for me that you rank Nodoka higher than her.
Nodoka, whether she likes it or not, is a character that causes a certain discomfort with her actions and she makes the story go in a direction that I didn't expect. The scene with Yumi, the beating she took, her talking about Io's trauma in the middle of the girls, her showing Sara who Sana really was and so on, are things that I didn't expect and that's what ends up making me like her, she moves the story towards a plot that I consider more interesting. So far I thought Sara's thing was awesome, like it was a really cruel way for her to find out about Sana and Akira and Haruka in that way, and that's what makes it so interesting, she moves the story in a completely different way than I expected it to go.
The scene with Yumi gave Yumi and Akira more development.
Her talking about Io's trauma "helped" her talk about it with Akira.
The scene with Sara will move the plot to something completely different, like, it will be the biggest turning point between the green and red paths.
It moves the story a lot towards the uncomfortable side, that's why I like it.
It's ironic that Yumi is my second favorite and yet I still like Nodoka ;-;