Takoyaki is a food; snack which you must try in Japan. Although Japanese restaurants outside of Japan sometimes offer takoyaki, but it is usually the frozen ones.
Tako means octopus and yaki means "to fry" or "to grill". Ingredients are not only diced octopus, but also batter(flour, egg and water), scallions, red pickled gingers and tenkasu(tempura scraps). Then, takoyaki is cooked using the special takoyaki pan; a griddle with half spherical molds. Cooked takoyaki are topped with takoyaki sauce(sweetened Worcestershire sauce), aonori(green laver) and shaved dried bonito. Some people put mayonnaise too.
Takoyaki is a soul food of Osaka and all families in Osaka have the griddles at their homes. In addition to, the griddles can be either electric versions or kitchen stove versions.