Hello, at min 1:18 of the 3.1 trailer there are botoms/legs that i can' tfind anywhere, could someone help me identify them ?

https://youtu.be/dkRTO7co_Yc?t=1m18s

The set (body/boots) looks like falconer, but the botoms are something else, looks like a skirt with leather socks. The game is lacking general purpouse zettai ryouki options, so this would be welcome. I hope it is also fully dyeable and not only a part.