In the town believed to be the first place in Japan to produce soy sauce (蝉丑艒测耻 in Japanese) 鈥 some 750 years ago 鈥 this factory lets visitors in on both ancient and modern production techniques. You're free to observe the factory; be sure to ask the desk staff for a pamphlet in English. Afterwards, try samples, and 蝉丑艒测耻 ice cream, in the gift shop. The factory is about a 10-minute walk from JR Yuasa Station (on the JR Kinokuni line).
The factory also offers a hands-on experience: for an extra 楼300, visitors can don a worker's happi and stir, with what looks like a long oar, the vat of gloppy miso that the soy sauce is made from. Make contact in advance to book: kuyou@yuasasyouyu.co.jp.