Kaidō Fuyama (伏山 灰道, Fuyama Kaidō) is a Shinigami and the Captain of the Twelfth Division in the Gotei 13. By extension, he is the President (会長, Kaichō) of the Shinigami Research and Development Institute. He is renown as a remarkably difficult individual to get along with due to being constantly engulfed with his scientific experiments, though his loyalties ultimately lie with the Gotei 13's desire to protect the Soul Society and maintaining the balance of Souls. Nevertheless, his consistently theoretical approach on virtually everything that can be mentioned in the Gotei 13 has earned him the title of Bookworm (読書家, Dokushoka) among the Captains, although lower-ranked officers seemingly refer to him by that title in private conversations.