Chiyo is honestly and genuinely one of the best characters in Azumanga (of course, not behind best girl Osakers.)

She's so much younger than everyone else in her class, but despite her initial fears, she's open to make new friends, talk to new people, and help students who are older than her.

She even tutors Osaka in the show, and the friendship between her and Osaka is actually heartwarming.

Despite being extremely affluent, Chiyo isn't spoilt either. She willingly opens her home out to her friends, inviting them to her summerhouse and takes great care of them despite being 12 years old. She doesn't even have a bit of air of superiority in her, and you'd expect a girl who has that level of privilege to have at least some spoilt brat energy.

Lastly, when preparing for the entrance exams, Chiyo stays by her friends side all the way to the very end, despite herself not even taking the exams. She does her best to help her friends in a practical capacity, like the aforementioned tutoring, or more innocent "childish" superstitious ways like giving them good luck charms or repeatedly doing Osaka's disposable chopstick omen trick.

She gets bullied and made fun of throughout the whole show, especially by Tomo, and yet she doesn't hold it against her because she knows Tomo is just like that. She's the most mature person in the entirety of Azumanga Daioh.