hiyoko is not a bitchy character, heres why

hiyoko as you all know, has a child like looks and rude personality but she just bitchy

growing up, she only looked up to her father but her grandma took her for the traditional dance practice.

her grandma was overbearing and never let her do anything by herself. like tying her kimono.

people also played over the top jokes on her, like putting thumbtacks in her shoes.

from all of this she grew into her rude personality to defend her self (i think she mostly bullies mikan cause she is reminded of her past self)

she tried to get better of course, like accepting fuyuhiko's apology.

that is all i have!! you can add more if you wanna!!