Chainsaw Man

[Buffalobiian]

Jujutsu Kaisen is different to this.

That episode has the Lawful Good fraction looking for a demonic presence. They run into the main character who is a teenager with a Grandpa who taught him right and has friends. That teenager got caught up in the supernatural shit. He gets immediately evaluated by his caretaker, and the MC demonstrates that he (kind of) has full control over going berserk because he shuts down his inner demon at will. The caretaker also takes the MC in because they are confident that they'll beat the shit out of it if it runs berserk anyway. They're also using the MC as a tracker/magnet/vault for related supernatural shit. The MC's drive is established quite early on as aiming to dispel his unfortunate supernatural circumstance.

This show is about a guy who owns a demonic pet, lives in a shack, and has been influenced by yukuza into paying his dad's debt with no apparent external help at all. He tells us in these last two episodes that when he does meet people they are repulsed by his unkempt state. He turned into a supernatural fusion being and killed a bunch of things. Now a caretaker with unclear motives takes him in. The MC's drive is jam-on-bread and boobs.

Both shows have an MC that encounters the supernatural, becomes tied up with it and joins an apparently lawful-good agency for reasons. Denji's "less ideal circumstances" vs Yuuji's makes sense given the difference in their premise.