Where does an expatriate living in Okinawa go for a two-week summer holiday? Why, to Tokyo, of course — if it's a working holiday — as there's no better place in Japan to make good money than the Big Mikan.

So, for the past couple of years since moving to Naha following the March 2011 disasters, I've spent two weeks of my two-month summer vacation from my university job in Naha teaching an intensive English-learning course at a university in Tokyo.

"Intensive" is the operative word here — three 90-minute classes per day, five days a week — actually the equivalent of an academic year's work for a once-a-week class — in just 10 days, with a weekend in the middle.