I'm surprised there isn't Ayane in the original question - she always struck me as a very kind character, just a bit more developed. Meaning, she had encountered hostility more and learned to stand her ground (e.g. against Kirin), which may make her look less kind (but doesn't really).
Since there was Noriko in the question and since I forcefully injected Ayane here, here's smth I've been thinking about: am I the only one who thinks Noriko and Ayane basically have the same personality, just with different life situations?
1. Both are kind to a fault. Ayane deeply loves people around her and seeing them getting hurt really gets to her, like finding Ami stabbed in the last reset or Maya getting reset now. Her default attitude to all around her is exceptionally friendly and, unlike other friendly girls, there is not as much room for jealosy (Chika) or anger (Rin comes to mind). Her kindness hurts her as she cares about Sensei to the point of tolerating him cheating on her and accepts other girls being in love with him.
Meanwhile, Noriko being a martyr is explicitly stated in the story, and it is quite convincing, so I don't even feel like recounting arguments.
2. Both are brave. Ayane keeps positive attitude in the face of timeloops and apocalypse, stands up to Kirin, and does a million more little things, like driving away Yumi when she picks on Futaba in the shower, etc. Noriko never gave up on searching for Sensei and was brave enough to show him Niki's old letters when she felt it could endanger their relationship but was a right thing to do.
3. Both are cheerful and friendly. Ayane and Noriko light up the room and make friends with the most unlikely characters, like Ayane with Sana or Noriko with Yumi.
4. Both obsess about Sensei and are fake yanderes initially. These are more superficial qualities, but they work even better in terms of proving similarities. Ayane and Noriko are the only ones who openly proclaimed their undying love for Sensei as soon as they got the chance. And they both at the start of their storylines seemed the craziest and the most fixated on him. Heck, as stereotypical yanderes they are the only ones known for constantly carrying weapons (Noriko's knife and Ayane's various assortment of guns and swords).
I do feel like they're the same character, just with different quirks and places in the story. There are, of course, little things unique to each one of them, e.g. Ayane wanting to have a shit ton of kids and Noriko being an idealistic rebel with creative (musical) drive. But these are details, and I feel like the only real differences are circumstantial - their situations being different. Noriko's story seems to be about unreciprocated (yet) love, being a martyr and a constant second place, and her keeping her rightiousness and idealism in spite of this. Ayane, I feel, is more about loving in the face of adversity - blackmail, cheating, competition.
And I wouldn't say that there is something wrong with these two having the same basic characteristics - unique situations are enough for their stories to play out differently and in an entertaining way. I'm just trying to sort out my own confusion about this, as I feel like I enjoy Noriko the most out of all the characters, yet there is Ayane, who is nearly identical to her in most regards, but she is somehow a bit lower on my tierlist.
What do you people think?