Hello everybody!! I don't remember the name of this manga, so please help me!

I'm looking for a manga shojo where the protagonist goes to another school so she's finally happy that the bully won't bully her anymore. But then, the bully appears in the same school (because he knew the girl would go there) and continues to bully her.
He bullied the girl as a child, he pulled his hair and show her insects. The guy has dark hair and the girl has fair hair. That's all I remember.

Thank you

Argh!!! I KNOW THIS MANGA...but...I don't remember the title of it off the top of my head.

I'm bumping this in the hopes someone could help us both

Bye-Bye Mitsubari Not 100% sure but some parts are very similar.

Were there like hamsters? And snakes? O-O
Nishiki-kun no Nasugamama vaguely fits.

Koe no Katachi
Not exactly what you're looking for but a bully situation turns into love after the main character grows up...