Kashiwaya, tucked off on a steep hillside along a winding, narrow road, will delight anyone wanting to devote their time entirely to soaking. There are 7 kashikiriburo (private reservable) rotenburo, meaning that you can leisurely dip in up to 7 different spots during the day. Most have direct views out onto the the river, and two are so close as to seem almost like you're bathing in it. In autumn, with maple trees seeming to burst into flame around you, it's a wonderful luxury to be able to sit at the edge of the river and let all your worries slip away.
That said, Kashiwaya is definitely not for everyone, and certainly not for those with mobility problems or weak knees. Several baths require navigating a maze of passageways and staircases, many of which could use a little TLC. Though only about 15 minutes' drive from nearby Shiobara Onsen, Kashiwaya is sufficiently remote so as to have no night life or even a nearby convenience store. Be sure to stock up on all necessary items before you arrive. But once you're here, really, it's a wonderful opportunity to really get away from it all, and the different baths mean that each dip holds something new and exciting.