I can't tell whether Rinnosuke is lying, or that there's a canon derp going on, since it's implied he's at least older than the Hakurei Barrier, and he would have to be good at magic in order to create the mini-Hakkero.
That aside...
> Well, unless Rinnosuke can help us find Marisa's house, this has been a waste of time.
> Althooooooooough... there might be something in this shop that might be useful for a future surprise. So let's look a little. We can't look too long, however. Marisa might return to her house soon. Hopefully the librarian is keeping her busy...
You don't have to be good at magic to tinker with a device. You have to be good at tinkering with devices. See: Kappa. Also to make a magical device you probobly just nedd knowledge about magic, and since Rinnosuke knows 'the name and utility of tools' he would probobly have an idea how a Hakkero would work if he had seen one before, which is suggested by the fact he claims he 'improved it from a normal one'. Basically, he could have simply reverse-engineered a Hakkero. His age is listed on the wiki as 'unknown, at least a few decades'.
> You guess since Rinnosuke said he knows Marisa's father, if he can't help you find Marisa's house directly, he can tell you where to find Mr.Kirisame who almost certainly would know.
> You take a look around the shop and see various odd objects that you do not recognize, as well as a few that you do. One that catches your eye is a book with a picture of trees and crows on the cover, and 'Ghost Stories' written on it.
> As you look at this book, you hear someone else enter the shop.
> "Kourin!" she said happily. You turn and see a bird youkai of some sort with silver hair, and blue patches, in it, fly in. She is wearing a black dress black and what seems to be a blue corset.
> She looks curious when she notices you and flies over.
> "What is this? Another customer? I've not seen this one before."
