Aeon's "HOME COORDY microwave oven storage container " introduced the other day as an "epoch-making storage container". I found a product from the same manufacturer at the 100-yen shop "Ceria", so I bought it.
This is the "Rakuchin-Pack" series manufactured by Inomata Chemical. At the store I visited, the capacities were 850ml (28.74us fl oz), 400ml (13.53us fl oz) (2 pieces), 270ml (9.13us fl oz) (2 pieces), and one set of rice (2 pieces), each in two colors, pink and brown.
The feature is that it can be heated in a microwave oven "with the lid on" by the company's patented technology. The heat-resistant temperature is 140 degrees and the cold-resistant temperature is -20 degrees, so you can take the frozen rice out of the freezer and heat it as it is.
In addition, because the lid is pushed into the container, the lid and body have a flat design with no grooves. It also has the advantage of being very easy to wash and dry.
In addition, there is a tab that makes it easy to open the lid, and a part of the main body is wide and easy to hold. If you close the lid tightly, it will be hermetically sealed, so you may want to use a large size lunch box.
The price is of course 108 yen each (tax included). The quantity of each is small because it is cheaper than Aeon, but it is also recommended for those who want a little!