As to why I couldn't have just gone ahead and cooked up the bento, this is because you not only have to cook components, they need to be cooked in the AM sometimes, but always need to cool before putting together the bento so that the other stuff doesn't get steamed.
For tomorrow there will be fried rice and onigiri which are rice balls, in this case stuffed with chopped up bits of chicken with a sauce. There is a name for it, but I can't for the life of me remember it.
Here is what one of her bento boxes look like. This is an "official" bento box, but you can use other containers too. I got this one from Jlist which is a Japanese mail order. Their shipping rates are very reasonable since they are in Japan.
This is a typical bento box you will find on the web. They come in other shapes too, but this type is most prevalent. On the top there is a cover for the whole thing, next is the big container which usually contains the food that goes with the rice plus a small dessert or something sweet. The bottom most container is shallower and is used for rice (usually). This set also comes with chopsticks. The black parts are the sealable covers. Even though this box comes with a carry container for all of this, I like to use a fat rubber band to make sure that the pieces stay together.