Hong Gu (洪古 [Japanese reading, ホン・グ], Hon Gu) is a military official who serves the High Eunuchs, but is aligned with Xingke's faction. He pilots a Gun-Ru. After Li Xingke's faction joins The Black Knights, he takes up the position of the 2nd Division Commander. He is last seen with Empress Tianzi and Zhou Xianglin in Ohgi and Viletta's wedding photo.
When Britannian forces arrive to aid the Eunuchs against the Black Knights, the High Eunuchs seize their chance to kill Tianzi, and get a new emperor to bend to their will. Hong Gu is participating in the battle, piloting a Gun-Ru. As the High Eunuchs' forces start closing in on Xingke's forces, it managed to take down Hong Gu's Gun-Ru.
After Zero's Knightmare Frame, Shinkiro, stops the Eunuchs from destroying the ship, Britannian forces pull out. Xingke charges in the Eunuchs' ship with the Shenhu, draws his sword, and kills them. Afterwards, Zero and Li Xingke become allies after parts of the Chinese Federation revolt against the High Eunuch. After the United Federation of Nations is formed, Hong Gu was appointed as 2nd Division Commander of Black Knights. After the truth of Zero’s identity and his Geass power is revealed and the betrayal of Lelouch, he, under the leadership of Xingke and along with the rest of The Black Knights, faces against Lelouch and the Brannian Army. After participating in the final battle together with the other leaders and members of Black Knights, he witnesses Lelouch being assassinated by Suzaku. He is last seen together in a photo of Kaname Ohgi's wedding with Villetta Nu.
Appearances in Other Media
Code Geass: The Manga
Hong Gu's role is similar to the one in the Anime. He participates in the Chinese Federation dispute and is appointed as 2nd Division Commander of the Black Knights. He suspects Lelouch's motives at Britannia's entrance to the UFN unlike Rakshata, from the Anime.
Code Geass: Oz the Reflection O2
Hong Gu was seen in the Chinese Federation with Cornelia, Guilford, Xianglin, Minami, Viletta, Orpheus, and Oldrin discussing about how to deal with both Lelouch and Marybell who is known in charge of the Damocles with the key and was decided that Cornelia's group go after Lelouch while Orpheus and Oldrin's go after Marybell.