The humble domestic kotatsu is enjoying something of a revival since the disaster at Fukushima made the nation painfully aware of the need to conserve energy. The device is a table with a heating element underneath and a warm blanket draped over it keep one’s legs nice and toasty; without using up excess energy, the kotatsu has been keeping families huddled together in the winter months since its charcoal forerunner first warmed feet in the 14th century.

But what about those living alone, who want to bring down their electric bill but might not have room for a large kotatsu table?

Enter the mini kotatsu heater from