Waki-honjin (‘assistant principal inns’) were similar to honjin except that they formed the second tier of inns in post-towns in terms of quality, size, and prestige.
Like the honjin, waki-honjin were open primarily to daimyo and other travelers of high status. If the principal inn was occupied, the waki-honjin took in the next highest ranking traveler. Most post-towns had one or two waki-honjin, but towns located at road junctions or other busy places frequently had more. Omiya, where it was possible to turn north off the Nakasendo to the Tokugawa mausoleum to pay respect to previous shoguns, had nine waki-honjin to serve the many important travelers on the two highways.
Although the honjin in most post-towns have disappeared due to fire and the immense expense of rebuilding or maintaining such a large establishment, the “waki-honjin” have not suffered the ravages of time so severely. They were large in comparison to other inns and buildings in the towns, but moderate enough in size for owners to bear the upkeep. Many post-towns, then, still have a waki-honjin.