There are five sets of five rules one must consider when attempting to make traditional Japanese food: the five colors (goshiki); the five methods (goho); the five flavors (gomi); the five senses (gokan); and finally the five viewpoints/considerations (gokan no mon), a Buddhist treatise on the proper way of eating and being grateful for food that has been prepared. Elements and variations on these dictums can be seen in all Asian cuisines that have been influenced by Buddhism. Originally codified in China, these axioms were imported, adapted and refined to fit the Japanese sensibility. They swayed the classically minded washoku chef for centuries.
In food, as in life, rules can restrict and limit us or they can guide and free us. Just as most artists determine the boundaries of the frame before setting out to create, when attempting to prepare food according to specific ethnocultural precepts one must also find out and consider the frame that surrounds the raw materials.
Some food preparations seem to evade classification and make it extremely difficult to determine a pattern for the entire cuisine. The classical Japanese ways, however, have made it simple and plain. But that simplicity has layers of variation and combination.