Nippon Suisan Kaisha is now offering this product called "Omu Rice" under their Nissui brand. It's an omelet filled with fried rice.
The thing is kept frozen, and then you nuke it to eat.
This particular variety is filled with chicken, rice, ketchup, chicken consomme and Worcester sauce. It's mixed with onions, carrots, green peas and sweet corn for texture.
My mom used to make me these things when I was a kid! She'd take last night's leftovers and throw it into an omelet for breakfast. Being Japanese, she always had steamed rice cooking each night. So, she took all the leftovers, tossed it in with the rice and fried it up. Then she'd prepare an omelet and fill it with the fried concoction.