The Song that serves as the ending theme for all the endings to Ar nosurge: Ode to an Unborn Star, excepting for its bad and true endings. While its title seems to be in Emotional Song Pact, it's also formed by words that in the Hymmnos Language translate to "This World, This Life". So not having found any means to go back to their worlds that didn't imply sacrificing anyone, they both gave their approval, and Cass sang this Song for them. Thus they became true inhabitants of the EXA_PICO universe, and it also became their final farewell to the worlds they called home...