This is amazing, stunning really. I saw this thumbnail in my inbox and i knew it was something good, and i was right. Shazy you never disappoint with your animations. although I've seen this pose countless times from the twins its still fun to see it turn out so well. the animation is well done, id say its as smooth transition for every movement. its not jittery or lagging at all. if you watch it enough times you'll notice a lot of work put into it. i mean, even their hair moves when the heads move, and the little sparkles that appear next to them, its just, damn its so good! bravo shazy. keep up the good work!
I think it'd be brilliant if it was less of a doodle/sketch and cleaned up a bit more and possibly colored? but that's just my opinion, i think it looks great either way.
For a sketch this is really good. The movement is fluid and the timing is done very well (I love how the arms kind of flick at the end as they speed up). I like the little details, like how they take a slight step as they move.
The gradient you've put over the lineart is really nice and helps to break the simplicity as well, considering it's just a sketch.
There are a few places where you lose/gain volume (expecially in the buttons) but that's fine because it's just a sketch. The one on the right (can't tell which is which xD), a flick of his hair suddenly jumps upwards on his head at one point.
Also, the one on the left. When his head is moving upwards in an arc, I think it moves too much to the left not to affect his shoulders. You should underexaggerate the head movement or move the top half of his body a bit more.
Other than that, it's really great~ Keep making more!
The right one is Hikaru. I know cuz not only is Hikaru ALWAYS on the right side, but in the beginning, he has the most mischievous expression on his face. Kaoru's is more like "idgaf". I love the animation, it's beautiful!