Nagase was a Jinki User who worked for F.L.A.G. and assisted in bringing Riku to the headquarters. When Riku was first brought to F.L.A.G. and escaped, and Takao entered the building, Nagase was told to find them. He managed to find Riku and Neene and managed to use his speed and Jinki to capture them, but Takao arrived and attacked him. Takao then proceeded to cut off his right arm before being quickly beheaded. Ironically, Takao called him "too slow" before he died, the same words he'd said when capturing Riku and Neene. Later he was mentioned again by the Chairwoman when she asked some workers if they wanted his cat, stating that his death caused his girlfriend to have a mild case of Lost Rebound Syndrome and was hospitalized. In the end, the Chairwoman ended up taking his cat.