Ugh. Do I have to tell these visual joke-tellers how it should be done?
The problem right here is that they used the word "Japan" twice. It becomes like a song where you're using the same word to rhyme with itself.

Worse, it sort of telegraphs the joke and the repeat syllables throws off the joke's cadence.
A much funnier joke would be "Are you from Tokyo?..." instead of "Are you from Japan?...". Go back to joke school.
Not bad. But it's hard to make a fake joke about women astronauts making sandwiches when there are real-life stories of women astronauts driving 900 miles in a black wig and a diaper to assault a woman with a drilling hammer, pepper spray, and rubber tubing at the Orlando airport. (
http://en.wikipedia.org/wiki/Lisa_Nowak#Personal)
Comedy lesson #2 today: don't make jokes about things where the real stories are even funnier. My laughter about sandwiches is completely tempered by the fact that I was thinking, "Well, at least she didn't drive 900 miles wearing a black wig and a diaper."