A collaboration game between Unisonshift Blossom and Accent featuring all heroines from all Blossom and Accent games.

One day, the heroines were transported to a strange place. They only found a living animal Uni, the mascot of Unison Shift. Uni explained that they can go back to their original worlds by 'unison power', a power that can be formed by singing together in unison. By ChuChu's advice, they decided to form idol groups to form 'Unison Power'.

Unison Stars is a game that uses Uno as the main gameplay.