Nintendo's Wii U console crossed the 10 million units sold threshold in the three-month period ended June 2015 (PDF link), while the console's new shooter, Splatoon, sold 1.62 million units.
Worldwide Wii U sales reached 470,000 units, compared to 510,000 units in the same quarter last year in the wake of Mario Kart 8's May 29, 2014 release. The Wii U was released in November 2012 and has struggled to sell, compared to Nintendo's previous consoles and its current competitors.
The console has been famously slow selling, though those Splatoon numbers are good news for Nintendo's newest franchise.
For comparison, it took the Wii a little under a year to sell through 10 Million units, as you can see in this fancy chart: