Japanese videogame giant Nintendo said today its first-half net profit soared to $132m as a sharply weaker yen boosted its bottom line and offset slowing sales. 

The Kyoto-based company earned 14.3 billion yen between April and September, up substantially from 600 million yen the same time a year ago.

This was despite sales falling 12.8% to 171.4 billion yen on lacklustre demand for its 3DS games system. 

Nintendo kept its full-year 20 billion yen profit forecast unchanged, and said its operating loss in the first half shrank to 215 million yen, from 23.3 billion yen a year earlier. 

The maker of the Super Mario and Pokemon franchises has struggled in recent years, as consumers flee to downloadable games for smartphones and other mobile devices. 

Net profit soared "as a result of exchange gains totalling 15.5 billion yen due to depreciation of the yen", the company said. 

A weaker yen helps make Japanese exporters more competitive overseas and inflates the value of their repatriated profits.