Benio Akagi

Benio Akagi (赤城ベニオ, Akagi Benio) is a young girl who joined the Black Knights following their reformation after Zero returned. She, along with her family, attended the ceremony for the Special Administrative Zone of Japan, where her parents died in the chaos, and she was saved by Kallen Kōzuki.

Code Geass: Lancelot & Guren
Benio makes her first appearance attending the opening of the Special Administrative Zone of Japan with her parents, having gotten lucky enough to get tickets to enter the stadium's main area. Her parents and Benio thinks that she can't remember the last time that her parents have been this happy, however, their joy is short-lived, as Princess Euphemia returns from her meeting with Zero, and asks all of the Japanese to die. Initially confused by her words, the crowd panics after she shoots a man, and the Britannian soldiers follow her lead. Managing to escape the chaos in the stadium, her father proclaims that the Black Knights will save them and to just run while her mother tells her to be brave. Unfortunately, in that moment tragedy strikes and Benio is knocked to the ground by an explosion, and her parents have been crushed by debris, leaving only a large splatter of blood where they had been. Stunned by the death of her parents, just as a Sutherland is about to kill her too, she is saved by the Guren Mk-II. Without time to process what is going on or a chance yet to feel sadness, the color crimson-the color of the stain on the ground left by her parents, and the color of the Knightmare that saved her life-is imprinted in her mind.

Some time later, she is taken in by the owner of a port inn in Kobe where she worked hard. She is then informed one day that she was to prepare a special room, putting in a brand new mattress and bed sheets and to put extra effort in the cleaning. Though she wonders who could be so important to call for such special treatment, she decides to be careful so as not to lose her job. As a boat arrives on the docks, her boss told her to come welcome their arriving guest, Kallen. Taking her luggage and leading her to the room, Kallen and Benio talk briefly before introducing themselves to one another. That night, as Benio goes to clean the warehouse, she stumbles upon the stored Guren Mk-II, instantly recognizing it and realizing Kallen is its pilot. She is then found by her boss, who instructs her to seal the door to Kallen's room from the outside. He tells to the confused girl not to asks questions, and says that these days not many Japanese can get by on kindness alone. Ignoring her instructions, Benio warns Kallen of the plan. Believing the girl, Kallen tells her to let her tie her up, so Benio won't be seen as an accomplice. Benio protests and begs Kallen to take her with her, who refuses. As the girl protests, Kallen tells her that if she really wants to help, that when the time comes to come to find her. Though Benio is confused, Kallen says that if they succeed, she'll know it, and goes to her Knightmare. Some months later, she witnesses Zero's return on TV, and leaves her job to go to Tokyo.

Benio is among the many from all around the country who come to the Black Knights refuge to join. Though she admits to herself that she is fine with doing basic chores, she wants to become a pilot, so that she could help Kallen, even if just a little. When she the day finally arrives that her and other recruits are to do mock battles, she meets Kagari Savitri, who is the one overseeing the course. Though nervous when introducing herself, she surprises Kagari by quickly eluding and striking her opponent. In the following battle, she then hits her second opponent with a series of paint rounds. Unknown to her, Kallen had arrived to watch the new recruits' training and was impressed by her skills. Seeing that other recruits won't be suitable opponents, Kagari requests any of the regular pilots of the Black Knights to be her opponent, and Tamaki volunteers. As the mock battle begins, Tamaki does not hold back against her and quickly overwhelms her. When others call him out for not going easy on a new recruit, he yells back that if she can't handle this level of attack than she would be instantly killed on the battle, and that this was his way of showing her kindness. Unwilling to give up yet, Benio continues the battle and attacks Tamaki several more times, though unable to land a blow. As it continues, Kagari orders the mock battle to end, and Tamaki says that he wants to but she just keeps coming at him. As Kagari is about to forcibly end the battle, Kallen stops her and asks her to wait just a little bit longer. In one last charge, she knocks Tamaki's Burai off its feet with her tonfas before passing out. When she wakes up later in the infirmary, she finds Kallen by her bedside. Kallen tells her that she has been assigned to piloting duty, and says that among all the new recruits today, she was the best. Kallen then thanks her for her help in Kobe, and Benio in turn thanks Kallen for saving her life, and tells Kallen it had been at the SAZ incident. Kallen then welcomes Benio into the Black Knights.

Kallen Kozuki
Benio looks up to Kallen, who sees her as a sort of younger sister.

Kagari Savitri
Kagari initially writes Benio off during mock battle training, though warms up to her over time. When the Black Knights relocate to Horai Island, Benio and Kagari are made roommates due to being the same age. When Kallen is captured in China, Kagari consoled Benio.