I'm not entirely sure what's going on with the Survival Senbei edible iPhone 5 case, but I'll do my best to sort it out despite a limited translation. The case looks suspiciously like a Rice Krispies treat wrapped around a phone, except it's made with a brown rice senbai cracker substance.
It seems you stick the case on your iPhone 5 and wait until you get so dangerously hungry that you're willing to eat a case that has been mixing with your greasy fingerprints and pocket lint. Yum.
Since the $48 case is essentially made out of snack food, the maker warns against too much direct sunlight or humidity. Those of you with sweaty palms might want to sit this one out.
The Survival Senbei case also won't do your iPhone 5 much good. It's extremely unlikely to survive a drop, much less cushion your expensive phone when it falls on the pavement. The case may not even survive shipping in one piece.
Each case is made by hand, which probably explains the price, though it fails to explain every other aspect of its existence.