Here is my 10 yen... I have two kids 13 and 15 who attend American School during the week and Japanese School on Saturdays. During the week they want to eat sandwiches just like everyone else and we like it that way because it's alot easier to prepare. On Saturdays, we have to follow the typical Bento process or else we get scolded AND all Japanese school children compare everyone's Bento box. Just last weekend, I prepared rice and gyoza but I forgot to add the sliced cucumbers, nori, furikake... One boy in my son's class mentioned, 'kawai sou ne' when he looked at my son's Bento contents. it means, 'i feel bad for you'. This is what survived our kids. this is our inventory of bento boxes: We have one with a vacuum valve, blue ice insert, dividers, multi-story w/hashi... This will save anything that could spoil on a hot day: I found these units at Tokyu Hands and they come in many sizes. The units consist of a container, a lid, a rubber o-ring (hollow), a blue ice retaining clip, and the blue ice. We never had anything go bad. No leaks either. As a matter of fact, nothing with an o-ring leaks and if they do, it's probably because external heat caused the internal pressure to increase forcing liquid to escape the seal of the o-ring -> content is probably spoiled. (again, never happened to us) Here is the lid with the cooling unit attached. These are the different sizes. Here is your basic Bento Box with fancy sentences. This one states, 'Leaflet tight, It is so wonderful to be able to maintain your dreams.' I like the single and/or double divider inserts. It keeps gooey things apart. BTW, I forgot to bring our shoyu and ponzu containers which are tiny fish with a screw-on cap. These are both too small to use today but for some reason we can't throw them away because they are sentimental? Or we are mental. Little of both. This unit is great for keeping things pin-pin-pari-pari fresh because it has that vacuum seal. See the red button? This the one I use for work. The top has a enclosure that houses a pair of hashi. The sides have your typical clasps which by the way fly open so you have to have the bag. You can see there are two containers in one so you can have your gohan in one level with your upper level with the main course. The discoloration is from repeated use in the microwave. Miniature muffin foil cups are a necessity to keep everything separated until it's time to dine. I can't find them anywhere in the US but if you go to Japan, go to Tokyu Hands. These dividers make you kids think they are at the train station in japan because every bento box at the train stations have these cool strips. Again, at Tokyu Hands. Sorry to clutter this up with so many pictures but I'm proud of my lifetime search for the ultimate bento boxes.