Sidu (しづ) (formerly romanized as Shidu), is an illustrator who had created various PVs, novels, and provides illustrations to various producers. Sidu often provides 'dark' illustrations, thus her most notable PV works being represented in the songs Abstract Nonsense, Tokyo Teddy Bear, and Enmei Chiryou by Neru, as well as the Kagerou Project series by Jin, and Setsuna Drive by Yoshimitsu Taki of 9mm Parabellum Bullet.
For the song Inochi no Justitia, she used the name Sakurai (作瀬). This caused a lot of confusion among the fans about her being Sidu or not. However, she later announced on her twitter that this was a prank that she asked Neru to operate with.
It wasn't until the middle of March 2015 that Sidu revealed her gender via her 1st Place official artist page, as well as the alteration in the romanization of her name.