Checking the video, that's Cirno on the left.
No idea who that is on the right.

KazuyaRazuKazama said:

Checking the video, that's Cirno on the left.
No idea who that is on the right.

Looks like original character this artist made for his video. This one I guess.

Edit:

The person on the right is a girl, sifting through the artist's submissions confirmed that, either that or the artist wanted to make an androgynous person