MATSUYAMA—At Dogo Onsen here, the iconic, 130-year-old main bathhouse reopened fully on July 11 after five and a half years of renovations and repair work. The historic building, the first ...

KUSATSU, Gunma Prefecture—In line with the glitzy spirit of the holidays, each night the traditional scenery of the Kusatsu onsen area now transforms into a fantastical world of light.

This is something I often cook for lunch. Even if you’re starting from scratch by making the onsen eggs (which you can also buy at some supermarkets), everything takes a maximum of 45 minutes to ...