Amy Kashihara, a refugee from the destroyed world of Valhalla now living in the human world of Rem, affiliates with the Rebel group opposing the Imperium. Her involvement with protagonists Jin, Akira, and Lena begins when she witnesses their successful summoning of a Gargoyle from an old book, recognizes Jin and Akira as DemiKids, and provides them with a Demiloc device for demon combat.

She suffers profound trauma after the Imperium executes Lena. Overwhelmed by despair, she surrenders to the Imperium, an act leading directly to her death. After the defeat of the final antagonist, entities Darklord and Lord Light resurrect her alongside Lena.

Expanded backstory reveals Valhalla fell during an apocalyptic conflict between demons and angels. Amidst this destruction, Isaac kidnapped Kashihara for a "final judgement." Manipulated by Shugoshin, she was deceived into believing she would become the deity of a new world intended to restore Valhalla; this world was actually designed to perpetuate the war between Light and Dark forces.

Her psychological trajectory is defined by profound loss and misguided redemption attempts. After Valhalla's destruction, she develops a self-sacrificial disposition, willingly aligning with Mephisto under Shugoshin's influence to fulfill the deceptive god role. This path positions her as a "martyr without a cause," highlighting her vulnerability post-tragedy.

In the anime adaptation *Shin Megami Tensei: D-Children Light & Dark*, appearing as "Ami," she actively summons Jin and Akira to war-ravaged Valhalla, pleading for their help to end the conflict. She guides them and participates in the quest to locate shards of the Time Chain, essential for restoring peace and creating a portal back to the human world.