Euphemia is the third princess of the Holy Britannian Empire and sub-viceroy
of Area 11. She is kind and sweet, and the half-sister of Lelouch and Nunnally, and the
sister of Cornelia. She is Lelouch's favorite half-sister. Soon after coming to Area 11,
she asks Suzaku to give her a tour of Area 11 and then the Shinjuku Ghetto. She is always
saying that she is worthless, but she is very brave risking her life more than once to
protect people. During the hotel hijacking, she risks life for Nina, and figures out that
Zero is Lelouch because he talks too much.
Soon afterwards she picks Suzaku Kurururgi as her personal knight because their
views are very similar. Soon after that Euphie, Kallen, Suzaku, and Zero are all transported
to an island when during a battle. Kallen was caught by Suzaku, and Euphie was with Zero.
Euphie then told Zero that she knew who he was, Lelouch. For about 24 hours Euphie was with
Zero, they were once again siblings. When they ran into Kallen and Suzaku, Suzaku was
giving Euphie in exchange for Kallen.
During Ashford's Academy open festival, Euphie runs into Nunnally and then Lelouch.
When she is talking to them Shirley sees them and becomes jealous, but the wind blows
and everyone sees that it's Euphie. When a mob forms around Euphie and a few of the other
military members in the area, Suzaku gets her out using a fifth generation knightmare. She
then announces her idea of the Special Administrative Zone of Japan in the region under
Mount Fuji, which gives the Japanese back their names and country back.