The shoyu is a sauce by itself and brewed of wheat, beans and salt.
The katsuwo sauce is prepared of the katsuwobushi and the shoyu.
In preparing the sauce, the katsuwobushi is simply chipped and simmered in a mixture of water and the shoyu.
Mohitori: officials who had charge of wells, shoyu (Japanese sauce) and ice-houses.
Chinese sauce may be used instead of shoyu which may be obtained at any Chinese restaurant.