Times are tough in Tokyo, too, but business is booming there at "love hotels." "I'd hate to use the term 'recession-proof,' but it's certainly proven very resilient over the last six to nine months," Steve Mansfield, CEO of New Perspectives, which operates six love, or "leisure," hotels in Japan, tells cnn.com.Yes, I thought we were talking about just spots for quickies -- but that's apparently not the case.Because of the population density in the country, it's mostly young couples who seek out the love hotels for privacy. "Even these days, on the weekend, every…