Talk:Cursed Sword/@comment-24768935-20161019143614/@comment-29602226-20161019191918

The idea behind Option 2 is that the girls are Mamono from birth, the just look human, like the Trumpart or the Nurarihyon or the Kejourou. All Mamonos who meet them recognize them as fellow Mamono.

They become adult, complete Cursed Swords when they choose a sword and infuse it with the DE from their own bodies.

It is the reverse to what happen to first generation Cursed Swords: First Generation Cursed Swords are created when a demonic blade infects a human woman, but those new Curse Swords are created when the Mamono girls infect normal blades.

EDIT: This is a theory of mine, not canon...