Kapa!!?

sorry Nitori, don't underestimate a shopkeeper skill and knowledge (especially Rinosuke in this manga, HE CAN MAKE GREAT WEAPONS Y'KNOW!)

That tengu girl is surprisingly cute.

abuse of abilities

Mary Sue powers activate

Let me guess... he plugged it in and turned it on?

YuriTenshi said:
Let me guess... he plugged it in and turned it on?

Nah, he opened it up, and looked inside, so probably just yanked the crumpled sheet of paper that was clogging it out of the rollers.

Well, if it's paper jam then I think she would never figure it out. No, I bet so. She's too into how the thing works.

Doesn't Rinnosuke have an ability to see an item and immediately know all of its functions? Or am I confusing him with another character?

He has the ability to know an item's name. After that, he pretty much guesses what it does.

More precisely, he knows what an item does, but not the why or how. This leaves him to make some insane leaps in logic to fill in the gaps of what he knows, particularly for more modern stuff.