Homura is a member of the Amanohokosaka family, a clan of Exorcists that descended from the Azure Shrine Maiden who had sealed the Black Beast before recorded history. Homura's mother, Tenjo, was the Imperator of the NOL when he was born. This, however, would be a short-lived life inside the comforts of the NOL as the Ikaruga Civil War reached its climax and Tenjo was assassinated by Jin Kisaragi during a coup d'etat spearheaded by Relius Clover, Hazama, Yuuki Terumi, and Meifang Lapislazuli. Thanks to the combined efforts of Kagura Mutsuki, Hibiki Kohaku, and several members of Sector Seven, Homura was smuggled out of the Ikaruga Federation by the former two, and led to an unknown location where they were safe from the persecution of the NOL. To many, Homura was assumed killed, but in reality, he laid patiently in wait, hatching a plan with Kagura to reinstall himself as the new Imperator and to overthrow the administration which had stolen his birthright.
It wouldn't be until the events of BlazBlue: Chrono Phantasma where Homura would appear in public. Kagura reintroduced Homura to Bang Shishigami, who had long believed Homura dead - they reconciled. Later on, Homura would be introduced to Jin and Tsubaki Yayoi by Kagura, and the both of them were convinced to join their side in the rebellion. By this time, most of the Duodecim had come to the side of the rebellion. 
The current Imperator, Izanami was aware of the rebellion before it could bear its fruits. Personally, she and Nine the Phantom went on to assault Homura and his guard, which consisted of Kagura, Jin, and Hibiki. Here, Izanami publicly abdicated her position as Imperator, and declared Homura as her successor before promptly disappearing to activate Doomsday.
During Doomsday, Homura attempted to hold the NOL together as many of its soldiers disintegrated into seithr as they were being absorbed into the Embryo. He was evacuated to the 4th Hierarchical City of Naobi into the Yayoi residence alongside the remaining Duodecim members. He also convinced Sector Seven to cooperate with the NOL in this time of peril.  It's unknown if Homura was one of the chosen who were chosen by Amaterasu to inherit the Azure, but both Hibiki and Mai Natsume were sent to guard him in case he was to be targeted during the disarray of the NOL. At some point, everyone naturally dissolved into seithr, but his information was stored by Es.
- XBlaze Code: Embryo, Es Route Episode 10
- BlazBlue: Chrono Phantasma, Chrono Phantasma Story Mode, Episode 12
- BlazBlue: Chrono Phantasma, Epilogue
- BlazBlue: Central Fiction, Story Mode, Chapter 1
- BlazBlue: Central Fiction, Epilogue