Kai Nageki (かいなげき, Nageki Kai ) is a rogue Shinigami that wanders the world of the living. Earlier in his life, Kai was the Captain of the 7th Division of the Gotei 13 during an era long past forgotten. He ascended to captaincy a short while after Shunsui Kyōraku and Jūshirō Ukitake began their days as captains. Kai was among the most noted of fighters within the Gotei at the time. At some point, he would meet his future wife, Mina In’ei. Life took a troublesome turn when he was given a special mission by his superior, Genryūsai Shigekuni Yamamoto, one of which he has not spoken of since being sworn to utter secrecy. For reasons unknown to even the senior captains, Kai fled the Soul Society with Mina to Naruki City of yesteryear.