I took my family to Kamogawa-kan in Chiba for a couple days to relax in the onsen hotspring spa and sunbathe. Here's the brochure and general look of the place. All Cypress wood and quite beautiful inside.
The below is a look at the front gate, and the menus for the kaiseki dinners (partial only). As well as a coaster with an artwork they own, of an "ama" diver gathering abalone, which was featured on the menu.