Gyudon (beef bowls)
Gyudon — thinly sliced beef simmered in soy-sake-mirin sauce over rice — is one of the cheapest and fastest hot meals in Japan. The three big chains (Yoshinoya, Sukiya, Matsuya) compete on toppings and side menus. A standard gyudon is roughly 470–650 kcal depending on size and toppings.