it takes place 16 years after XX, Ky and dizzy HAVE married and have a son named Sin who Ky sends off to train with Sol because Ky can't take his newly aquired position as king of Illyria and be a father.
Dizzy starts to dissappear because of somthing called thebackyard which is supposed to controll all existance. KY uses his lightning seal to imprison her in a state where time is frozen and he puts abounty on Sol (to get his attention.)
Sol meets a gear names Izuna on his way to ky and Izuna takes him and Sin to a gear that can explain the backyard. there they get attacked by Valentine who is a reincarnation of Justice (who is revelad to be Aria and Sol's wife, she was turned into a gear after SOl dissapeared and went insane because of it....also, Dizzy is Sol's daughter{revealed in the Overture Drama CD}) Valentine wants to get Dizzy's cells because they are the key to acessing the backyard (she wants to destroy all life except for her select gears) She kidnaps Sin and SOl teams up with Ky,Izuna, and Dr. PAradigm (the one who explaned the backyard). to rescue SIn.
along the way Sol runs into that-man who has taken on a younger body to maintain immortality, and he battles Raven.
after the battle with raven, that-man decides to help Sol for once and opens a portal to the backyard. there SOl fights the unleashed form of valentine and the justice form of Valentine.
after winning Valentine self distructs and SOl's party arrives back at the castle, there they start to search for a way to un freeze Dizzy.
the game then cuts to that-man saying that he or SOl will carry out the work of the devil.
the credits roll followed by a to be contenued.
