Chiaki Kuriyama, Hyde, and Hiroki Narimiya bring Ai Yazawa's best-selling manga to the screen in a touching tale of undying love written and directed for the screen by Ken Nikai. Mizuki (Kuriyama) is about to turn 19, though the tragedies of the past year hardly seem worth celebrating. Still reeling from her mother's recent suicide, jilted by an unfaithful boyfriend, and betrayed by her closest friend, Mizuki is left all alone in an unforgiving world in which even her stepfamily seems coolly distant. Now the only thing left to do is leave it all behind and start life anew, and upon arriving at a dilapidated estate which seemed to beckon her from afar, Mizuki makes the acquaintance of mysterious and melancholy musician Adam (Hyde). His familiar melodies stirring something strangely irresistible within Mizuki, Adam soon sets the troubled young girl on a determined path to solve a mystery two decades in the making before the waning moon goes dark.