Konparu-yu

This bathhouse first opened in Ginza in 1863, during the dying days of the Edo period, and it hasn't made much effort to update its retro stylings since. There's an old-fashioned reception desk on the way in, and an impressive mural of Kutani porcelain tiles depicting carp, spring and autumn flowers and birds that you can enjoy while soaking in the tub. There are two baths, one pleasantly warm and the other heated to a fairly toasty 42° C. Twice a month they float flowers in the baths, so it's worth checking the website before you go.