Cyan Hijirikawa longs to join the band at school, but is too shy. While worrying about it at home, she's transported to another dimension…

Plasmagica hasn't performed enough concerts to play in the Grateful Rock Festival, and Aion's gloominess is causing problems with his bandmates.

The day of the Grateful Rock Festival has finally come, and as the bands get ready to perform, Cyan worries about the dark monsters...