/jp/ - Otaku Culture

We don't know Mima's backstory.

But we do know that when we first saw her, she was a ghost.

More specifically an evil spirit.

Wearing a tattered sailor uniform and carrying a big bloody knife.

Sealed in a shrine outbuilding.

Which was in Hell.

And when she got out, she was bent on taking revenge on all humanity.

Even if we don't know and probably will never know her backstory, it has to have been pretty darn bad.