The Kagerou Project / Kagerou Days (カゲロウデイズ Kagerou Purojekto / deizu) is a series of songs by the Vocaloid song producer Shizen no Teki-P,who is also known as Jin.. The series has two novels and a manga adaption that connect all the songs together.

The songs tell the story about Mekakushi Dan, a group of teenagers with unusual powers, called "Eye Abilities".

Most songs are sung by Vocaloid IA, while the earlier songs were sung by Vocaloid Miku Hatsune. The project started at February 17, 2011 when the first song Artificial Enemy was uploaded to Nico Nico Douga.