Very impressive hand movements for the Chunithm-like gameplay from Silver Wolf. Not only that, it's also accurate and not just tapping on the pads as far as I can see.

Edit: chart also very overcharted.

Popurika has written a quite in-depth making-of article on Fanbox going into the details of the production starting from the concept, to the used addons for Blender.

Fanbox: HoYoHoYoにしてあげる MV (Archive.org)

I just noticed some clever details.

At 497/23 when Silver Wolf gets her long break, she notices Miku is starting to have trouble. She says something to Miku, points to herself then to a region of the keyboard, the part of Miku's side closest to Silver Wolf. To which Miku responds with a >:) face and a nod. I'm fairly certain Silver Wolf is offering to take over on that section, to which Miku agrees. This means Silver Wolf is covering roughly 2/3 of the keyboard to Miku's 1/3.

Starting around 524/028, Silver Wolf does seem to have taken charge of part of Miku's side: several times when Miku gets two simultaneous inputs, Silver Wolf covers for her by reaching well past the centerline to hit a note on Miku's half of the keyboard, her left hand blurring when she does so. This continues until 734/054, which is when Silver Wolf starts to become overwhelmed and goes @_@. She misses an input... only for Miku to handle it herself in the nick of time, remembering she has a right hand in the process. Miku then stares at her right hand for a few moments as if she's never seen it before. Quite funny.