Social psychologist Ben Monroe has returned to Tokyo after a failed marriage, determined to seek out his former lover Kozue. His estranged teenage daughter Mazzy reluctantly flies from California to join him. On the flight she meets a young Japanese man, Koji, a cult survivor, who tells her the story of the luminous night princess Kaguya, a powerful tale of beauty and obsession. As Ben delves deeper into the underworld in search of Kozue, Mazzy and Koji are compelled to follow, and their four lives dangerously intersect as past and present collide.