Produced by studio Sunrise, Code Geass is an anime that was released well over a decade ago. It follows the story of exiled prince Lelouch vi Britannia, a young and extremely ambitious young man who one day finds himself in possession of the power of complete obedience. He uses this power to get the one thing he truly desires — the freedom of Japan from the evil empire of Britannia.
The series was a hit from the get go, and like many other popular series among fans, it had certain characters that many ended up hating. While a lot of the hate towards character was an intentional byproduct of the show's creators (seeing how the characters were evil people), a lot of the hate was directed at some completely unexpected characters.
10 Shirley
The problem with Shirley is the same problem as with most female characters in this series – their existence seems to revolve around one boy or the other. Shirley has a huge crush on Lelouch and goes to great lengths in order to catch his attention. Such is her level of entitlement that she gets annoyed at girls who have normal conversations with Lelouch.
9 Ohgi
Despite being the leader of a Japanese resistance group, Ohgi has consistently shown a lack of ambition. Even though he's prideful of his lineage, he'd rather be a teacher in a peaceful town than be heading rebellion against Britannia. His views changed a lot after he witnessed the massacre of the Japanese by the Britannians, but he never let go of his dream, which was viewed as a weakness and hindrance by many fans.
8 Diethard
Diethard is the personification of the modern day paparazzi — people who stop at nothing to get the scoop that they want. While this is good for journalism, this often resulted in many moral and ethical boundaries being crossed.
Not to mention the fact that he didn't think twice before falsifying facts in order to get what he wants.
7 Tamaki
Despite Tamaki being on the side of the Japanese rebellion, and despite his people consistently being part of racist attacks by this Britannians, Tamaki himself could not let go of his racist ideologies. He hated all Britannians without exception. He was also bratty and impulsive, as was seen when he went against Zero's orders and ordered the execution of the Ashford Academy student council.
6 C.C.
The problem with her is how she is used as mostly a plot device, and nothing more. She's there to give Lelouch his powers, but she herself is shrouded in mystery and nobody knows why she does what she does. She is shown to be a lonely and detached person who rarely expresses herself emotionally. Due to this, many fans found it difficult to form an emotional bond with her.
5 Prince Schneizel
Despite his good looks and charming nature, this young man is shown to be an extremely cunning and manipulative person. He has no regard for the life of any person, even those who are close to him. The best example of this would he him gunning down his younger sister, who he was the closest to — Cornelia. He does not show remorse or regret for all the murders he's committed.
4 Lelouch’s Father
The 98th emperor of the Holy Britannian Empire, Charles zi Britanniawas, who is shown to be Lelouch's father, is shown as an antagonist from the get go.
Even though his belief is correct — the fact that deceit is the cause of evil, his execution of this belief (by annihilating all of humanity) in order to have peace in this world, is what makes him a truly evil man.
3 Nunnally
Nunnally vi Britannia is your typical shounen sister character trope — someone who's completely useless, offers nothing to the plot but exists to show how weak women are, and how their only worth in shounen series is to view them as loving sister/mother tropes or the sexy/tsundere love interest trope.
2 Suzaku
People who love Lelouch hated Suzaku, and for good reason. Even though Zero's methods may be questionable, he was getting a job done that absolutely no one else would. However, Suzaku's blind loyalty to an empire that treated his own people no better than livestock, his betrayal of Lelouch and his stubbornness to turning a blind eye to his own actions, is what makes him the number two most hated character from the series.
1 Nina Einstein
Initially, Nina was a shy classmate of Lelouch's. However, over the course of the series, she evolved into a character that fans could not get behind. She invented the nuclear weapon of mass destruction, FLEIJA. She shows no remorse or constraint while using the weapon, kills innocent classmates because of a personal grudge, and is an all around racist who believes in the decimation of every other race that stands in her way. Nina takes the cake when it comes to being Code Geass' most hated character.