I used it with my 1 year old and my family of 3.
Kobuchizawa is nearby, and shopping was convenient as there was a supermarket nearby. The area around the site has a villa-like atmosphere, with a stream running through it, so we were able to relax without worrying about children's voices.
Also, the cottage was very clean, especially the water area, tableware, and bedding, which made me feel comfortable. Towels, toothbrushes, hair dryers, and cloths are also provided, so you won't need to bring much. The sleeping area is in a loft, so you need to be careful with small children, but my child was fine because the bed was in the back!
At the BBQ, you can borrow lanterns and there are mosquito nets, so the children can have a comfortable time without being bitten by insects.
Above all, the owner was very kind and that alone made me want to visit again. I would like to stay for several nights next time!