My favorite autumn dish is kuri gohan–a delightful mix of Japanese white rice and sweet chestnuts, typically sprinkled with some black sesame seeds and a pinch of salt. The combination of the chewy rice and the natural sweetness of the chestnuts is elite.
You can easily make kuri gohan yourself if you have a rice cooker, but otherwise, Tagosaku (typically found in department stores and near train stations all across Japan) offers one of the tastiest store-bought versions I’ve had.
Tagosaku menu: https://www.ghf.co.jp/en/brand/sanwa-tagosaku/menu