Steam your own lunch over hot spring vents
In some of Kyushu's hot spring areas, such as Beppu, steam at about 100°C rises from the ground, and people cook with it in a style called jigoku-mushi, or "hell steaming." Set vegetables, eggs and seafood in a steam oven yourself, and eat them hot beside the clouds of steam.
Buy ingredients here or bring your own, and steam them in a basket over the hot spring vents. A steamer costs 400 yen (small) or 600 yen (large) for 15 minutes, given out in order of numbered tickets with no reservations. There is also a foot bath and a foot steamer.
A roadside farm shop in Kannawa, Beppu, where you choose fresh produce from Oita and steam it yourself in the steam ovens on site. Vegetables and eggs are sold here, so you can eat them straight from the steam; ask first if you want to bring your own food.
A hot spring in Takenoyu, in the mountains of Kumamoto, where you set your food in one of the steam ovens before your bath and it is ready when you come out; steaming is free for bathers. It has 17 private baths you can rent by the hour.