Hareniwa no yu

Looks like an indoor glamping site with a bath. The cosmetics were what stood out for me at this facility. My favorite part of the indoor bath was the clay mask. I kept it on and lay on the deck chairs outside. The outdoor tubs (three) had very hot water, but it may be because of the atmospheric temperature difference between the inside and outside. They had free flavored water too for the guests. Kids could also play in the tree house they had installed.

Award winning spa in rugby town Kumagaya. Eight different types of baths, loads of lounging areas, hammocks, tents, tree houses, bouldering, cafes and a stylish glamping play area. More than 10,000 books and manga. Great for families. Reasonably priced. Free parking. You'll find even more detailed information on insaitama blog.

Not much experience in this kind of place, but it's really kids friendly, and beyond Onsen you can eat, drink, play, rest, and even sleep over there. It's very clean. They've put 159 plastic ducks in a shallow bath (only 4 of them stand right though).

Totally different atmosphere from other Japanese style hot spring resort. Everywhere is full of outdoor elements, camping, BBQ and wild grass. Good place for people who want to stay overnight!

Amazing place, never been in a place like that, unfortunately the onsen is prohibited to people with tattoos... but had a good time there