Witch hat Atelier RPG!

The primary antagonists are the Brimmed Hats, a group of rogue witches who reject the strict rules governing magic.
Without spoiling later developments:
they believe magical knowledge should be free
they use forbidden spells
they're responsible for many tragedies in the story
their philosophy isn't entirely unreasonable
The series spends a lot of time exploring whether restricting knowledge actually protects people—or simply concentrates power.

Coco:
Curious, compassionate, and endlessly creative. Rather than being naturally powerful, she's talented because she questions assumptions and invents new ways to think about magic.
Qifrey
Coco's teacher.
Gentle, patient, and mysterious, though it's clear he has secrets and personal motivations beyond simply teaching apprentices.
The other apprentices
Agott — talented, proud, initially abrasive but deeply layered.
Tetia — cheerful and optimistic.
Richeh — quiet, thoughtful, and kind.
One of the series' strengths is how these four gradually become believable friends instead of remaining simple archetypes.

This is probably the series' biggest strength.
Instead of chanting spells or throwing fireballs, witches literally draw magic.

A spell consists of:
geometric circles
symbols
patterns
magical ink
careful craftsman.

Changing even a tiny line can completely alter a spell's effect.

It makes magic feel closer to:
architecture
engineering
calligraphy
graphic design
programming

than traditional fantasy wizardry.
Learning magic is treated like attending an art school or trade workshop—which is why the title uses the word "Atelier."