No. It is a man-made structure. Usually of cement and concrete, lined with tile, built with drains. Humans fill it with clean water, to bathe in. It is considerably larger than a bath tub.

[ Dorothy pauses. A lot of people had pets, here, and while she was getting more used to that, and all the animals naturally around them, it still surprised her a little. She wasn't quite used to people outside the hyper-rich having them. ]

Her name is Satori. She keeps to herself most of the time. You may have met her sister, Koishi.

[ May have, of course. She knew the youkai's powers made it hard for people to remember her. ]