Now imagine opening the tin lid and getting the chopsticks out to eat what should be steaming hot rice—but it’s cold and somehow tasteless. Want to avoid this disappointment? That’s the idea behind insulated bento boxes, known in Japan as dan-netsu yoki. Options from Thermos, Tiger, Luntus and others can be found at grocery stores, variety shops and any number of sources online, allowing students and workers to enjoy steaming rice just as they would at home.

These boxes may be round or square, narrowly shaped to fit in a salaryman’s briefcase or blocky enough to hold a child’s rice balls on a school trip, with special features to keep salad dressing from spilling. Regardless of age, gender, profession, the bento box has the flexibility to accommodate one’s personal needs of convenience and necessity—and ensure that the rice comes out hot!