Japan's First Single-phase Watt-hour Meters

Supply of electric power to homes in Japan began in 1887, with electric lighting coming into common use around 1907.

However, at the time the watt-hour meters were not produced in Japan but primarily imported from General Electric in the United States.
In December 1914, the Kawasaki Plant began assembly of single-phase two-line watt-hour meters.
The next year, on July 7, 1915, the company was able to obtain authorization for its I-14 single-phase two-line watt-hour meter (100V 5A), and it brought this model to market in September.