"I'm not sure. It'd be interesting to test."

"Name a tattoo and a color you won't hate if they stick."

"Three horizontal red lines, on my right shoulder."

Lines?

He pulls his sleeve aside. The lines appear and then crumble in a fine layer of ash.

"Huh! I wonder -" He tries the lines again but in surface makeup instead.

That works.

"Okay, so on top of the skin is fine, under it even a little and poof."

"Possibly it's reacting to disruption of the physical material."

"But you can still bend, a tattoo doesn't do more disruption than that."

"I think it's related to self-conception as triggered by material disruptions - moving is actually different than when alive, I have to intend to move in a different way mentally."

"Oh! That sounds complicated."

"It isn't too different from how I manipulate chakra without hand signs, but I suspect it'd be a steep learning curve for a civilian."

"Have the others had any trouble with it?"

"Not that I've seen, but we were all lifelong shinobi."

"I was assuming they didn't all do your specific look-no-hands trick and might not happen to have anything equally compensatory up their sleeves but perhaps many things can be compensatory."

"I think it's mostly that it ends up being a very short learning curve."

Nod. "Oh well. I hope you weren't dying to be tattooed."

"I already did the ones I wanted in life," he says, tilting his head in a way that makes the three red marks on his face - one thin red triangle on each cheek, and one on his chin - stand out a bit more.

"Classy."

"They represent my brothers."

Nod.

"Did you have other experiments you wished to perform now?"

"Nothing else lined up."

"I can't think of any either. I'll contact you if I come up with something, though."