After sacrificing himself in a heroic act, the not-so-angelic Yusuke Urameshi awakens in the Spirit World. Due to a clerical error, he must prove himself by undertaking tests to become a detective under Koenma, the Spirit World ruler's son. When Koenma is abducted, Yusuke must abandon his summer plans to rescue him, facing the peril of a potential upheaval in the Spirit World. With his allies by his side, Yusuke ventures to Magma Valley to save his savior and uncover a malevolent plot threatening the realm.