Reijirou Yuuki, known by friends as Rei-kun, a boy notorious for being late to school, is suddenly hit by a truck and killed on one of his many rushes to class. He then roams the earth as a ghost, only being visible to his classmate Kodama. Reijirou finds himself and Kodama in many adventures involving his ability to possess, and gets himself tangled up with the lives of his classmates and friends, including Takeshi Gama: the bully, Kaoru Tachibana: the perfect transfer student with a secret, and Bell: the demon working a part-time shift as a shinigami.

Later in the series, Reijirou goes beyond his neighborhood to other parts of Japan with Bell to raise his reincarnation credit score, leaving Kodama behind.