Very awesome mechanical details behind the armors. ^^
This is a Wave Direct web limited release. Pre-order period has started since December 25th and will end on February 28th. Late April release, 21,000 Yen (inclusive of tax).
Only for the first batch of production, Yen-Xing will be offered as a set of three, featuring Unit 1, 2 and 3. Each of them will have a different shield. All three models in the set are the same though.
Also, Wave has a special tutorial page up for assembling and painting this resin kit. It's a good guide for folks interested in getting this kit.
All images are from Wave.