Most of us have dyed t-shirts before in school or at camp, or maybe have even bought a cool tie-dye shirt at the store. But what if you could do tie dye at home without ever using a washing machine?

A visual expression of happiness in fabric form, tie-dye, in all of its Technicolor glory, is the kind of mood boost we need now—particularly as we’ve been stuck in the same-old confines of home.

Arimatsu, in central Japan, is the town that tie-dye built. Along its historic main street, fabric merchant houses have stood for centuries. When shopkeepers hang out their shingles here, the signs ...