Shido Itsuka has spent four seasons sealing Spirit powers by winning their hearts; in this fifth season he finally faces Mio Takamiya, the First Spirit who granted him that ability in the first place. Buried memories of a previous existence as Shinji Takamiya begin to surface, tracing his connection to Mio back to an origin the Ratatoskr organization never knew about. Kurumi, Tohka and the other Spirits close ranks around him as the story reaches its final arc.