Tomoharu Natsume survived a horrible plane crash but Misao, his close friend, did not and became a ghost that continued to be attached to him. Three years later, he moved out to a place rented by his brother to live on his own and attend Raku High since his mother remarried. On his first day in his new house, a mysterious girl called Shuri turns up and gives him a silver briefcase to look after on behalf of his brother who lives abroad. Soon after, Tomoharu and his best friend, a ghost named Misao Minakami, are attacked by various factions who all seek the 'Asura Machina' and 'Extractor'.
Tomoharu Natsume sobrevivió a un horrible accidente de avión, pero Misao, su amigo cercano, no lo hizo y se convirtió en un fantasma que seguía apegado a él. Tres años después, se mudó a un lugar alquilado por su hermano para vivir solo y asistir a Raku High desde que su madre se volvió a casar. En su primer día en su nueva casa, una chica misteriosa llamada Shuri aparece y le da un maletín plateado para que lo cuide en nombre de su hermano que vive en el extranjero. Poco después, Tomoharu y su mejor amigo, un fantasma llamado Misao Minakami, son atacados por varias facciones que buscan la 'Asura Machina' y el 'Extractor'.