The cool part about this is that it uses the Leap Motion to detect your hands and can therefore use the gesture to open the menu (two finger down swipe), just like in the anime.
For the moment it is a neat way of using a menu, although not the most efficient if you are in a hurry.
This type of GUI would be best in an RPG where you have all the time you need to go through your inventory to check your items.
Still, it did make me squeal for joy. Having a menu you can navigate with your REAL hands is freaking cool!
I can only imagine the amount of coding that must have gone into this.