no, the power is older but i guess that is like the normla witch powers, one student is chosen to be the original witch and while she is in that school other student will awake powers, and when that original witch graduate another in first year will born, or maybe shiraichi is a magical being that will live forever and she is always in that school erasing memories of her being in that school so when she graduate, she can start again in firts year, maybe thats why she doest seen to have a family, maybe she never had one, and thats are my two theories i think the firts one is the most posible because i dont think this is the kind of manga that would introduce a real magical beaing this late in the game
I thought the witch power were older, but they only existed as long as shiraichi was in school Σ( ￣□￣||)