Azuki (小豆) beans are small red beans, primarily used to
prepare anko paste for using in Japanese confectionery.
While normal azuki beans are quite small -- the kanji for the name in fact even mean "small beans" -- the variety known
as Dainagon azuki are considerably larger and highly
esteemed for preparing quality anko.
The beans also have a few unexpected uses. Baskin-Robbins Japan
makes a truly excellent azuki-flavored ice cream using
Dainagon beans, and azuki can also be abused to make
amanatto, a sweeter form of the infamous natto.