"I am a Libra of Libras" - I could have stopped reading there. "...the interview was over and I was leaving the room. As I shut the door behind me, the committee erupted into laughter" - of course they did. He probably had just told them that alignment of planets made him suitable for the job.

Relevant SMBC: http://www.smbc-comics.com/?id=3634#comic

I have the suspect that "libra of libras" shouldn't be intended necessarily in its literal sense (of astrological sign), even if it were true. The symbol of the libra is a scale, so the author is just saying, as made clear in the next period, that he usually keeps his moods and opinions very balanced between the positive and the negative, in contrast with the fully optimistic attitude he sees in the Americans.

In japan they ask you for your blood group on job applications

That's odd. At least, they don't ask about astrological signs. I hope that they don't. "I am a Libra of Libras" sounds like "I'm a crackpot of crackpots" to me.

That's odd. Your comments in this thread sound like "I'm not intelligent enough to identify a metaphor" to me. Strange how those things work, isn't it?

The blood type obsession thing is basically their version of astrological signs. Wikipedia has more about it:

http://en.wikipedia.org/wiki/Blood_types_in_Japanese_culture