Anko

Anko (餡子, often shortened to an/餡) is sweetened azuki bean paste, the single most common ingredient across wagashi. Azuki beans are simmered until soft, sweetened, usually with sugar, and mashed or strained to a paste, then used as a filling or standalone base for sweets like daifuku, dorayaki, manju, and yokan.

Anko comes in two main styles, distinguished by whether the bean skins are removed. Koshian is strained smooth, with the skins removed entirely. Tsubuan keeps the beans whole or coarsely mashed, skins included, for a chunkier texture. Neither style is more “authentic” than the other; the choice is regional and situational, and many wagashi shops offer both.