It looks like a hot pot and is a hot topic on SNS! Have you checked out the "Bonur" series of lunch pots that you can buy at the 100-yen shop "Ceria"?
It seems that there are 4 sizes in all, but I got two food containers with a capacity of 150 ml and a mini cup (capacity 18 ml, 3 pieces), and of course the price is 100 yen (excluding tax). Two colors, red and cream white, are available.
The food container is the right size to hold a side dish or fruit. The lid is packed tightly so it is safe to carry (be careful not to turn it upside down or tilt it). There are some caveats, but you can also use the microwave and dishwasher.
On the other hand, the mini cup is a seasoning container for lunch boxes such as ketchup, mayonnaise, and sauce. The lid is attached to the case so you don't have to worry about losing it. Microwave oven and dishwasher cannot be used here.
At lunchtime, of course, you can add sugar or milk, or stationery, and it's cute even if you use it like miscellaneous goods. It looks just like the lunch box "Cocopot " that I introduced earlier, so you can carry it with you. If you are lucky enough to meet, please pick it up ♪