Pickled with koji. 麹漬け。
Koji is a mold that is cultivated on rice and that is responsible for the sugarification of the starch in the rice as well as the production of other enzymes.
A pickling method for winter.
Best example: bettarazuke, using daikon. Has a sweet flavor and alcoholic aroma. The name derives from the "stickiness" of this type of pickle.