I just bought these new boxes from Ichiban Kan. They are from the Putifresh grape series, and have some awesome Engrish: "Happy fruits is very delicious. I will eat this and will become fortunate all together!" The one on the left is two tiers, 350 mL and 250 mL, and has space in the top lid for my little fork, and something small, like chocolate squares. The box on the right has a snap-top lid which makes it spill-proof. It holds 480 mL, which is more than enough soup (or whatever). Also, both boxes are microwaveable.
I also bought some more elastic bands to hold my boxes together, two bags, some furikake, a spring roll kit, and some cookies, and my total was less than $20!