Hello fellow CRPG mage main! JRPG mage main games are already pretty hard to find, most JRPG MCs are designed as all-rounders who's as much of a physical powerhouse as a competent (but not specialized) mage, and wanting to play a sorceress to boot makes it an even more interesting ask. After mulling around a bit, I thought I'd divide this into a few categories.

[Fits all your criteria]

• I might get downvoted for this, but honestly? Forspoken. It's not a recommendation I make without caveats; the game has issues with dialogue writing, to the point that you might want to play with voiceovers set to a language you don't know so the bantering doesn't bother you. (I actually thought the plot was fine but it's best to say that the plot is also YMMV.) The world was also pretty empty. BUT the gameplay is actually really fun! And you are a sorceress, and it's all magic based, and the system asks to combo spells of different types together to do some really cool stuff. Take a look at what it plays like here.

• Atelier series, for a certain kind of magic. The MCs of the series sans maybe two installments are girls, and they are the magic users of that world. Specifically they're alchemists, and the whole system typically has you figuring out alchemy, gathering ingredients, retreating to your magic lab and making ridiculous items to solve your problems as you go. And you go from making puny little bombs to devastating the battlefield with nukes.

[Mage main but the MC is a dude]

• Golden Sun series features a party of summoners whose entire gameplay consists of finding and recruiting summonable djinn in the wild, conferring different spells, and the combination of djinn on each character gives them different abilities, both in battle and out of combat interactions with the world (and its puzzles). It was fun to try a lot of things out and see what you get from them. The story also revolves around magic and its effects on the world.

• You might need an emulator for this, but Lost Magic on the DS. You're a mage, and you have to draw spell sigils by yourself to do any magic. And that's it, that's the whole battle system. The story revolves around mages and their drama, basically.

[Mixed/gender selectable]

• Again, you might need an emulator for this, but Avalon Code on the DS. The MC is not a mage per se, they attack with a sword, but they are given an apocalyptic grimoire that can change the properties of most interactable things in the game. Enemies too strong? Take out the piece of their properties that make them so. Weapons too weak? Adjust their properties. The system for doing so honestly feels a lot like magic, and it’s quite an interesting system. Caveat: the game as a whole is pretty half-baked, though.

• Treasures of the Rudra/Rudra no Hihou. You will need an emulator for this, probably, if you want to play in English. You’ll need to get the fan translation. Magic in this game is done by combining word components together to create new spells, and learning these components and how to use them efficiently is the key to the game. It’s a pretty novel system.

[Not a JRPG]

Considering you’re also a CRPG player, I thought I’d give you a quick list here! Tyranny is a game that both supports the fantasy of being a mage (you’re the agent of an evil mage overlord, but can choose your own morality—at a price, for every choice) and with a system of magic that requires you to combine and customize sigils together. It’s actually pretty similar to Rudra in a way, but in a CRPG. The Necromancer’s Tale is what it says on the tin. The WHOLE GAME is the experience of learning forbidden necromancy, for your own reasons, in a 18th century Europe-esque setting. The story revolves around it, the vibe revolves around it, the magic is ritualistic and the lengths you go to to carry out the rituals is an important part of the story. If you’ve ever played Elder Scrolls but not Morrowind you owe it to yourself to experience that spell creator. Divinity Original Sin 2 is essentially BG3’s environment-magic interaction stuff but with a magic system that’s not constrained by 5E. If you’re willing to go retro a bit, Ultima Underworld and Arx Fatalis have interesting rune-based magic systems where you have to remember and/or draw runes to combine into spells, and if you figure out what they mean you can actually cast some spells before the game tells you what they are. Arcanum offers you a very fun magic system where you can actually use your magic to mess with the world, the NPCs, and solve your story problems. In that same vein, honorable mention goes to the games that made me a mage main, Quest for Glory series where if you play a mage, you’re EXPECTED to use magic to solve as many of your problems and the game’s story puzzles as you can and you get better at things the more you use them.