It seems to be useful for lunch in winter. I found a kitchen item called "Food Pot DELI 320ml (10.82us fl oz)" at 3COINS. I bought it because I was attracted to the cuteness of the colon.
A stainless steel food pot that helps keep food and drink warm and cold. The capacity is 0.32L, and the heat retention effect is 50 degrees or more (6 hours).
The mouth of the container is designed to be slightly squeezed. If you add cup soup, you can mix it well without worrying about spilling. If you add rice, pickled plums, salted kelp, etc. and pour hot water, it will be a dish like Ochazuke. Even during busy work, you can eat without worrying about getting cold.
The price is 1,080 yen (tax included) per piece. In addition to white, there are black colors. How about using it as one of the bento items?