Kingyoku is a traditional sweet and a type of wagashi. It is made with agar that's sweetened with sugar or sugar syrup and left to solidify in a mold. During the summer, kingyoku is made so that it looks like a goldfish pot – there are colorful balls that look like stones or plants (usually nerikiri, another type of wagashi), and bright-colored goldfish made from bean paste.

Both are placed inside the transparent agar so it looks like they're floating inside. The agar (kanten) in kingyoku is known to have a cooling effect and it's very refreshing on the palate, which is the reason why kingyoku is especially popular during summer.

Other ingredients such as egg whites, coarse rice powder, and arrowroot can all be added to kingyoku, depending on the variety, such as the one colored with red bean paste that represent the ground, while the sky portion of the agar is colored blue.

Due to the fact that kingyoku is small, wagashi-makers need to have a great level of skill in order to achieve the appropriate level of detail for this refreshing summer sweet.