Inside the museum, a renovated compression factory from the early Taisho era, antique tools and panels clearly explain how soy sauce is made from raw ingredients. One of Japan's largest gassho-style buildings, it's a registered tangible cultural property and is home to many highlights, including the "Okoga Tunnel," a giant wooden barrel carved out of a concrete slab. The tour takes about 30 minutes, making it an indoor tour that can be enjoyed even in the rain.

On the premises, you can view the adjacent moromi compression factory from the terrace, and just a few minutes' walk away, you can get a bird's-eye view of the warehouse, lined with rows of wooden barrels. If you're lucky, you might even get to see the brewing and production process in action. After your tour, head to the product center to try some limited-edition soy sauce or the addictive caramel-flavored "soy sauce soft serve."