My first post was in haste, as I misread the message on the piece.
I see now that the writing on the thing says: "I believe this is a Japanese war bond application." and "Take it down to the laundry and see if you can get some white shirts size 15-34."
That second part means either that the person who wrote it believes it has some cash value, with which to pay for the shirts, OR that while getting shirts (neck 15, sleeve 34) at the laundry someone there could be asked to identify it further.
As for all the writing in Japanese, there's no one here and there never has been who could read all that.
I've seen Japanese war bonds, but I've never seen an application for war bonds, so you could do Google image searching on such to see if you can find something that more or less matches what you have.
