Is this what one would refer to as an "upwardly mobile" cafe?

Wow, I doubt that would ever meet OSHA regulations... Gotta love Japan!

This cafe is running 24 hours a day 7 days a week. It's a "sit-in" to block development of the Northeast corner of the Yoshida campus of Kyodai, which would destroy the stone wall. This wall has a 50 year history as an info. spot for students. It played a focal role during the student demonstrations of the 1960's and even nowadays you can see anti-war placards sometimes.
The university administration claims the billboards distract drivers. The students (mostly affiliated with Yoshida dormitory wish to protect the history and culture of the campus.

Others are reading more into this. With the re-militarization of Japan always a possibility, the authorities may wish to do all they can to forestall possible demonstrations.

There are some photos and links here:

http://www.livejournal.com/users/sparkligbeatnic/25252.html

BTW the coffee is 50 yen and it's really good. Recommended!

Does the coffe taste interesting, slightly comedic?

You know, I didn't even bother to read the other signs, so I completely missed that. Thanks for the extra info and pictures.