Only 3.38 million Wii U consoles were sold between April 1, 2014 and March 31, 2015, down by over 200,000 units from Nintendo's full-year forecast of 3.6 million.
Furthermore, Nintendo does not expect sales of Wii U to pick up by much during FY 2016, forecasting a marginal improvement to 3.4 million units. This year's sales were up on the previous year, however, which stood at 2.72m.
As of March 31, 2015, Wii U had sold a combined total of 9.54 million units worldwide.
The console does have some modest success stories, though. Mario Kart 8 has sold 5.11 million units since its release last year, while Super Smash Bros. for Wii U managed 3.65 million units. The popularity of Mario Kart saw the game bought by more than one in two Wii U owners.