It's a small shop in an alley, but the service is excellent. They are very patient and give you plenty of tips.

We got a 130,000km old car, barely made it uphill, very stinky and with a leaky air con that made driving with 38dgs outside a nightmare. The staff didn’t really speak English and the only thing they made clear was that upon return the car needed to be refilled in a specific gas station and that they would need to check the invoice. Unsurprisingly this has station had the most expensive gas in Kyoto, 20¥/ltr more than anywhere else! A rent a car to avoid!