[He'll also take this time to just stick his sword back into his bag so he doesn't attract too many weird stares while they're out and about in the city. An explanation, while he does so:]
They're basically object-spirits, I think? It's a legend that if something's around for a hundred years, it'll grow a soul of its own. I think the stuff's usually treasured too, so like, a rock that's around for a hundred years prooobably won't become a tsukumogami. It's like chairs of kings or that famous tea caddy thing or swords that samurai used a lot.
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[He'll also take this time to just stick his sword back into his bag so he doesn't attract too many weird stares while they're out and about in the city. An explanation, while he does so:]
They're basically object-spirits, I think? It's a legend that if something's around for a hundred years, it'll grow a soul of its own. I think the stuff's usually treasured too, so like, a rock that's around for a hundred years prooobably won't become a tsukumogami. It's like chairs of kings or that famous tea caddy thing or swords that samurai used a lot.