The tiny Teikoku-yu is a real gem located in downtown Tokyo. With a koi carp theme running throughout its interior, the tiles are painted with fish, and the ponds in both of the changing rooms are home to little fish swimming. The sento, which was built in 1916, was badly damaged in the war, but was then restored to its former glory. It was renovated again in 2023.

Teikoku-yu features wood-fired bathing waters, a cold water bath and a hotter one. The outside resting spaces are open on both sides of the facility, so when you’ve had a bath you can chill out while admiring the shrubbery. The sento reception desk is in the traditional bandai style, with one member overseeing both changing rooms.