Megumi Fushiguro!

Megumi is a tall young man, measuring 175 centímeters at 15. His hair is a dark Raven color, neat and spiky. He has green eyes, pale skin and his body is well built.

Cold, reserved, he has trouble expressing his emotions, he's very fond towards animals, he's quiet, but he's really attentive and respectful. He wants to protect all kind people. He's also analytical and thoughtful.

His cursed technique is the 'Ten shadows technique', technique inhereted by the members of the Zenin clan, although most of them don't have it. He uses shadows to create advanced shikigami or contain objects. To use an invocation it has to be exorcised first so if a shikigami is destroyed, it can't be used again unless it's fused with another.

Megumi was born outside the clan as Toji's trump card and was eventually found by Satoru Gojo, who mentored him and enrolled him at Tokyo Metropolitan Curse Technical College, also known as Jujutsu High as his student.

She's his step-sister, he loves her dearly, and she's just two or one year older than him. She doesn't studies at jujutsu high. Since she's his step-sister she doesn't has any cursed technique or energy.
Due to her little-to-no knowledge about curses, she fell into a comma after going to a 'haunted' bridge and being attack by one. Unluckily, she was the most affected by it.

Basically monsters born out of non-sorcerers or evil sorcerers. Either way, they're invisible to most people and they're often in haunted places. They're dangerous to a lot of people due to them being invisible to most of them, thus the person attacked by one is defenseless.
Only sorcerers can see them and actually know their existence.