Cycling to work banned

Well, it hasn't been yet. But it has been threatened. This is at a Govt
funded (quasi-independent, the management structure is somewhat obscure)
scientific research lab in Japan (http://www.jamstec.go.jp/frsgc/eng/).
The main goal of the lab is the understanding and prediction of climate
change, and it issues plenty of warm fuzzy statemente about "Protecting
our Mother Earth", but when the bureaucratic chips are down, it seems
that it is more important to issue diktats and invent rules to outlaw
one of the most environmentally-friendly behaviours possible.

The real reason behind this is that my wife and I are recidivist
criminals. Yes, we ride a tandem (we both work at the same lab). It
seems that way back in the mists of time, some careless bureaucrat
drafted a law that was intended to prevent more than one person riding
on a standard bicycle, but which accidentally included tandems in the
prohibition. (Despite the law, carrying a passenger is very common, and
of course no-one enforces such a petty nonsense anyway.) Some
prefectures have actually changed the law to allow tandems, but
unfortunately not the one where we live and work.

Anyway, we rode a tandem before we came to Japan, and continued after
our arrival a few years ago. Some bureaucrat noticed this immediately,
and made disapproving noises, but we ignored him - he refused to give us
an official FRSGC badge for the bike, but we found this apparent
reprimand surprisingly easy to cope with. Three years later, and he (or
perhaps some replacement) is back with a vengeance. He has insisted that
we cannot continue to ride the tandem to work. If we continue, he will
ban all cycling for all members of staff. The justification for this
escalation (and whether is it in principle legally possible) is not
clear, and we haven't told any other cyclists yet. We don't want to stop
riding the tandem, as it is faster, safer and easier than riding single
bikes, and more fun too. People recognise us on our regular route, and
are friendly towards us, plus we've got a good tandem (um...3 tandems)
and no suitable single bikes. Every day we pass the same police boxes,
we have even met some policemen and of course they are not bothered
about us "flouting" such a petty, trivial and obviously accidental law.

In Japan (in a clear contrast with the UK), the commute to work is
partly the responsibility of the employer. For instance, an injury
during the commute counts as a industrial accident, and the employer
must pay for subsequent medical bills and sick pay (the latter which for
non-work-related injury and illness does not appear to be a statutory
requirement, or even part of our generally reasonable working
conditions). It is not clear to me why this responsibility should give
them the right to dictate methods of travel to work, but I have heard of
another company where driving to work was banned, and someone was fired
after having a crash and getting caught.

In the UK, I would happily tell the bureaucrat to **** off, but
unfortunately workers' rights are still a rather foreign concept here
and it is clear that any foreigner who kicks up too much of a fuss gets
sent home in short order (I have already caused more than my share of
trouble, and now is definitely not a good time to start any more).
Bureaucrats aside, I like it here, and am not in a rush to leave. But I
don't take kindly to small-minded petty jobsworths trying to push me
around. Any hints and tips for a sensible strategy will be gratefully
received.

James