Borrow / rent / buy used Mountainbike in Kyoto?

Hi!

I'm in Kyoto for 3 weeks in October and I would like to do some bike tours. Any tips on where to get a used mountainbike?

Or maybe one can be borrowed or rented cheaply?

For example we have "Kleinanzeigen" (online flee market) in Germany, where you can easily find a bike in your city for a low price (I know of Craigslist but there is nothing?!)

Thanks!
-Philipp