During the early years of his unit, Valkyrie, the unit themed themselves around the concept of a marionette theater, with the unit leader, Shu Itsuki, as the puppeteer. Correspondingly, Shu would be in charge of Valkyrie’s productions, outfits, choreography, and discography to a meticulous degree. Mika Kagehira, dedicated to bringing Shu's art to life, found pride in being one of Shu's "dolls".