Lost Song tells the stories of the cheerful Rin and the reserved Finis, two songstresses who are capable of performing magical songs. Rin grew up in a remote village with her family and was taught to keep her power secret, while Finis lives and performs in the royal palace. Rin's happy and peaceful life is shattered after she saves an injured knight named Henry Leobort with her song of healing. She was seen by soldiers who proceeded to attack her village in hopes of capturing her. With nowhere else to go, she and her inventor brother Al begin a journey to the capital. Finis finds herself falling in love with Henry and, knowing that the greedy and spiteful Prince Lood Bernstein IV desires her, must hide their relationship. She wants to help people with her songs, but with war on the horizon, she worries that Lood will order her to cast her magic in the battlefield. Only time will tell how her destiny and Rin's will intersect, as the two of them struggle to find their paths.

Millie Nocturne has one great goal in life: to be the best in the universe - at absolutely everything! But when she tries her hand at being the best detective, she ends up an unwilling partner with two people who will change her life forever: Kane Blueriver, the psi-blade-wielding master of the starship Swordbreaker, and Canal, the smart-mouthed holographic image of the ship's computer. Join this unlikely trio on their adventures as they hurtle through space facing off against intergalactic crime lords, rogue starships, and hijackers dressed as chickens... and that's just the tip of the asteroid! (Source: RightStuf)

Tensions from the Selector battles have seemingly vanished, and the remaining participants have quickly put the entire ordeal behind them. However, Kiyoi Mizushima feels that the conflict has yet to end. Despite Kou Satomi's defeat, his supporters are already attempting to revive his plans in the background. It does not take long for Mizushima's suspicions to be confirmed true. Not only does the Selector battle system reemerge, but also a new mechanic has been implemented. Players receive a special key card that will unlock with gold coins, releasing a hidden power. Aware of the formidable foes that lie ahead, Mizushima begins to seek out skilled allies in her endeavor to finally break the cycle of darkness.

Having moved away due to family circumstances, Suzuko Homura returns to her hometown, nostalgic about the cheerful childhood she shared with Chinatsu Morikawa. Forever sealed with a promise of friendship, those days remain a bright memory to Suzuko, yet she has lost contact with Chinatsu during their time apart. Ready to start anew, Suzuko endeavors to put the past behind her and make new friends at school, but she struggles to do so. Meanwhile, Chinatsu is working multiple shifts to support her family as she continues her studies, and the mounting pressure to meet high expectations soon becomes overwhelming. Amid their respective situations, both girls begin playing the popular card game WIXOSS and discover that they have been chosen as Selectors—players whose memories are now represented by gold coins and must battle other Selectors to earn five of them. Guided by their LRIG avatar cards, which are created from the user's memories, the two learn that inconsistently partaking in duels or losing all their coins will result in a grim outcome. Resolved to protect what they hold dear, Suzuko and Chinatsu prepare for the battles ahead and fight for the chance to reclaim themselves.