"DONUT HOLE" is an original song by Hachi. Singed by GUMI.
He released it after almost 3 years absence in the Vocaloid community.

Source:https://vocaloid.fandom.com/wiki/ドーナツホール_(Donut_Hole)

The signature scene of the original Music Video is the chorus when the characters have a mugshot with something that appears to be face Paint, this scene in the parodies often changes the pattern for a reference o something related to the character in question.

A notable fact is that the artist Saintbullart made a Fan MV of the song featuring the ECHO VN characters both adult and young versions, Syndey included, plus a few cameos from Sam.
Thanks to this Fan MV Echo project hired Saintbullart to make the sprites of the Younger version of the main cast with a similar artstyle from the video and maked canon the artist's desing of syndey