From Edo Culture: Daily Life and Diversions in Urban Japan, 1600–1868, by Nishiyama Matsunosuke, trans. and ed. by Gerald Groemer (U. Hawai‘i Press, 1997), 163-164:
After so much talk of famine, we too need some relief. Let us turn next to the food that travelers ate at the fifty-three stops of the Tōkaidō highway. In 1817 Yamagata Heiemon Shigeyoshi, the master of the scholar Yamagata Bantō (1748–1821), was summoned by the lord of Sendai. Yamagata left Osaka by boat on the eighteenth day of the first month and then traveled on highways to arrive in Sendai on the twelfth day of the second month. In his detailed travel diary, he recorded exactly what he ate at each of the inns at which he lodged.
For lunch on the nineteenth, while looking out over Lake Biwa near Atsuta, Yamagata ate corbicula soup; a dish of carrots, burdock, and kelp; and a dish of trefoil dressed with white sesame sauce. Toward evening he arrived at Kusatsu in snowy weather; here it was so cold that even the lamp oil froze. Supper consisted of a vinegared dish (namasu) of giant white radish (daikon), persimmon, and greens; a soup of greens and dried bean curds; a hira of kamaboko, gourd shavings (kanpyō), and burdock; and a broiled salted mackerel. The next morning he ate white beet soup; a hira of Japanese cabbage (mizuna), shiitake mushroom, and dried bean curd; a choku of pickled salted plums; and a roasted dried fish. Yamagata crossed Suzuka Pass in heavy snow and spent the night at the bottom of the opposite slope: the twenty-first found him in Kuwana; the twenty-second, in Miya. Although the surroundings changed considerably, food on the Tōkaidō highway stayed basically the same at every inn. As soups, hira, tsubo, or broiled fish were not varied by introducing locally available specialties, the cuisine was quite monotonous.
This was an official trip. Travel expenses for Yamagata and his attendant, a doctor, five porters, three packhorse drivers, and three horses were probably paid by the lord of Sendai. Thus meals at each post town must have been of a high quality. Although one must take into account that Yamagata’s journey took place in the middle of winter, the lack of variety in the cuisine is surprising. Soups always included giant white radish, either fresh or dried; the hira always featured combinations of dried gourd shavings (kanpyō), tofu, burdock, carrot, potato, kelp, shiitake mushrooms, and, as recorded on a few occasions, dried laver (nori) and kamaboko. The tsubo consisted of kokushō; of tofu boiled in water, soy sauce, and sake; of burdock; or of light wheat gluten cakes. Broiled fish usually meant mackerel, young sea bream, sole, or yellowtail. Exceptional meals included the eel served for supper at an inn at Arai and the “fluffy eggs” eaten for breakfast at Fukuroi. Today Japanese travelers would tire of such fare in two or three days. Such cuisine gives us yet another insight into conditions on the Tōkaidō during an age in which the pace of life was much slower than it is today.
Once Yamagata had passed Edo and headed for the northeast, some local color appears in his meals. At Kasukabe broiled carp (funa) was served; at Odawara he ate a wild duck. Broiled fish was almost invariably salmon or gurnard (kanagashira), but at Koshigawa he received dried cod flavored with sake. Nevertheless, both soups and hira featured nothing out of the ordinary. Even the fact that udo (probably yamaudo) was eaten at the stay at Kasukabe on the fifth day of the second month seems remarkable in this context. If high-class inns on the Tōkaidō and Ōshū-kaidō served this kind of fare during the late Edo period, one may assume that both the quality and preparation of food at townsmen’s homes must have been quite mediocre by today’s standards.
NOTES: Although I was familiar with kinpira (金平 lit. ‘gold ordinary’), I wasn’t aware that hira (平 ‘level, plain, common’?) could be used for all types of similarly prepared (sauteed then simmered together) vegetable dishes. Perhaps tsubo (壷) ‘pot, jar’ dishes differ from nabemono (鍋物 ‘hot pot‘) by being prepared in the kitchen rather than at the dining table. Kokushō (濃く漿, ‘thick sap/serum/plasma’?) seems more commonly known as 重湯 omoyu (lit. ‘heavy hotwater’) ‘thin rice gruel’, like okayu (お粥) ‘rice gruel, jook, congee’.