Years ago, when a friend of mine was preparing to move back home to Los Angeles, I helped her clean her rented studio apartment in Tokyo. Shoving aside a pile of books, clothes and various other kinds of clutter, we wiped the wood floor, scrubbed the bathtub and polished the kitchen sink. We spent almost a whole day tackling the spots and stains that had cropped up over the years, until both of us were exhausted, both physically and mentally. Yet my friend was still worried whether she had made enough effort to clean up the unit.

"I don't know what the Japanese level of cleanliness is," she told me.

While there is probably no single standard for cleanliness in Japan, or anywhere else for that matter, the state of cleanliness in which a renter should leave their apartment when they leave is a rather prickly issue, often resulting in legal trouble. Some unscrupulous real-estate agents also charge exorbitant "cleaning fees" from departing renters (often in the form of cuts in the amount of their deposits or security money they get back at the end of their rental agreements) if they don't clean or repair any damage themselves — even though some of that might be illegal.