Not a smartphone youkai?

The Zashiki-warashi, Shiki!

I am the sage of the Reiga Consultation Office,

Amaazing! Tell me more!

Shiki-chan, you're amazing!

Wha...? I'm... amazing?

So this is a fox's spiritual power, then?

Zashiki-warashi, you see, bestow fortune upon dwellings they inhabit!

That this locale has not gone out of business is down to my presence!

But you use the wealth you bestow in smartphone games, don't you?

I think it's more that she's just really a good girl at heart.

It's a fox!

A-And you see! This here is what you call a "youko"!

A-Ahem! I am quite the knowledgeable one!

Fox youkai are called "youko", transform into humans, love playing tricks, and after they live a number of years, their tail count changes...

Wikipedia Zashiki-warashi