Genbu Kururugi

Genbu Kururugi (枢木ゲンブ, Kururugi Genbu) is Suzaku's late father, the last prime minister of Japan, and host for both Lelouch and Nunnally vi Britannia seven years prior to the beginning of the series.

Character History
Before the beginning of the series, Genbu Kururugi was the Prime Minister of Japan and the father of Suzaku Kururugi. He later receives Lelouch and Nunnally as hostages. When Britannia began its invasion of Japan, Genbu refused to surrender, preferring unending resistance against Britannia. It was reported in the media that Genbu Kururugi had committed suicide in order to stop the all-out war against Britannia.

The only other times Genbu was seen, was during flashbacks and when C.C. transmitted memories into Suzaku during the Battle of Narita.

After Suzaku and Lelouch save Nunnally from Mao, Suzaku planned to arrest Mao. However, in order to get a chance to escape, Mao uses his Geass on Suzaku. He reveals that Genbu Kururugi was actually murdered by his own son. He planned on a do or die resistance, however Suzaku killed him believing that it would stop the war. In the aftermath of that incident, the truth behind Genbu's death was covered up in order to protect Suzaku. Not only did Lelouch know the truth but others like Kallen Kōzuki and Euphemia li Britannia knew as well because Suzaku had told them. Others like Schneizel el Britannia suspected what happened between Suzaku and Genbu. Suzaku once noticed how Lelouch's eyes were similar to those of his father due to the fact that they were willing to take punishment by lying until the very end.

Zero
In the novel "issue zero" it is revealed that Suzaku killed his father months before the fighting officially started. After hearing that his father will sacrifice the Japanese military by refusing to surrender to Britannia, Genbu also plans to kill Nunnally as a political favor to an un-named member of the royal family. The thought of his closest friends being killed is what prompts the ten year old boy into action. Taizo Kirihara and Kyoshiro Tohdoh were the only others at the scene who knew about what had actually happened.

Nightmare of Nunnally
In the Nightmare of Nunnally, Genbu Kururugi was killed by C.C..

Suzaku of the Counterattack
In Suzaku of the Counterattack, when Suzaku hears him talking to the Britannian emperor selling out Japan, he kills him.

Trivia

 * Both Genbu Kururugi and his son, Suzaku, have the same names of two of the Four Symbols in the Chinese constellation; Genbu being the Black Tortoise of the North and Suzaku being the Vermillion Bird of the South.