The jubako box made its appearance during the Taisho period, and lacquer or other material was used in an effort to create the impression of luxury, so that even today unaju in a jubako box tends to be more expensive than unadon or unagi-donburi in a bowl.
重箱を使うものは大正時代に登場し、漆器を使うなど高級な印象を与えることを狙ったようで、現在でも鰻丼と比べると価格が高い傾向がある。