There is a slight regional tendency that mochi are baked before being used in zoni in the areas to the east of the geotectonic line of Shizuoka-Itoigawa. the fact that they are not baked in the areas to the west of the line is often mentioned to point out a difference in eating habits between the east and the west in Japan, however, the difference is not so distinctive, because regional variations also exist within each area.
また糸魚川静岡構造線以東は焼き餅で、西は焼かずに入れるという傾向があるものの、個別の地域差が大きく、これだけで割り切れるものではないが、日本の東西の食習慣の違いを表わす例としてよく持ち出されるものでもある。