I probably would have stayed in one on my first visit to Japan, however, my gender made sure that the options available to me were extremely limited. So I never bothered.

I'd guess that the amount of capsules available for ladies are way less than 10% of the total in Tokyo.

Why not hold on to this fantasy for a year or two longer and stay in one of the 'new generation' capsule hotels planned for London & other cities (perhaps re-imported to Japan eventually).

details here: www.yotel.com