It's a rather special dish from the Setouchi coastal region of Higashi Ward in Okayama City, made with pumpkin.
Pumpkins have been cultivated in this area since the late 1800s, and this warming dish became an essential part of their meals. Especially during the difficult times of World War II and the post-war period, when sugar was hard to come by, it was made by utilizing the pumpkin's natural sweetness.
While its origins are humble, it's now a cherished traditional dish in the Saidaiji area. Modern Nankin Zoni is made with sugar, resulting in a truly delicious and heartwarming dessert.