This is a lazy animation of William and his unalived siblings (I feel so cruel) so they're (from youngest to oldest) William, Scarlett, Will and Stella (there's also Warthur, but he was unalived and got replaced by William) PRESS GREEN BUTTON TWICE SO THAT IT WORKS
Btw the lyrics say (translated to English from Russian(I speak this awesome language :3)) Senpai! Sh-sh-sh-she showed her mom my photos. So what did she say? She said that I'm weird, she said that I'm weird, she said that I'm weird, she said that I'm weird, that she shouldn't walk with me.