KOEI TECMO confirm that they are starting development on Nintendo's new console codenamed "NX".— ZhugeEX (@ZhugeEX) April 28, 2016
No project announced just yet.
@GoldMetalSonic Basically they've confirmed that NX is one of the platforms they are now developing for— ZhugeEX (@ZhugeEX) April 28, 2016
(No idea when they actually started)
As the tweets state, Koei Tecmo is making NX software. We don't know what they're doing or how many projects they have in the works, but at least we're off to a good start!