Shitsurakuen (失楽園?, literally Paradise Lost) is a shōnen manga series written and illustrated by Naomura Tooru. It follows the story of Himoto Sora, a transfer student with a sense of justice and dreams of becoming a knight. Upon arriving at Utopia Gakuen, she learns of a virtual reality-like game played by the male students in which they use girls as weapons in battles for status and treat them as commodities. Seeing one of these girls being abused she steps in and though some sort of error unwittingly becomes the first female participant of the game.
Sora is the lone female participant in the Exaclan game and is tasked with the overthrowing of the male dominance system. She is honorable, but not very bright. Wishing to be a knight and to protect the princesses, she even tells X, when asked to “possess and protect”, that there is no way she would own a princess.
Tsuki is Sora's closest and best friend. She is a mysterious figure, the brain behind Sora's brawn. She is possessed by L and thus can collect information about Exaclan. She is also the currently apparent target of X.
Koharu is Sora's first princess. She is wholly devoted to Sora and plans to help Sora, overthrow of the male dominance system. She most recognized physically by her large breasts. She is one of the six “stars” and her weapon is a rifle.
Yuki is Sora's second princess. She was the first girl Sora observed in a battle, when Sora first arrived at Utopia Gakuen. She was afraid to stand up, but was given hope when she saw Sora and Koharu. She is physically characterized by her long, twin braids. Her weapon is a dagger and is considered rather weak.
Tomoko is the first girl that Sora gave to Karin. She did not want to be in the minority and could not handle being bullied so she asked Sora to release her. She is given to Karin. But L tells Mitarai to torture Tomoko until the very last moment before the final stage of the warning penalty. Later she is released by Karin and once again possessed by Sora after being rescued by her in the woods. She is one of the six “stars” and her weapon is a spear.
Reiko is a girl previously owned by Sumita of the student council. Sumita approaches Sora and fights her, but lets Sora win. Reiko did not want to be Sora's possession, so after confronting Sora, she was released. She goes back to find Sumita and go back to him, but is caught by Shoujou and becomes Tougyu's possession, who tortures her. Sora eventually found out, and decided to free her by using the warning penalty. It worked with the help of Sumita. Reiko's eyes are said to be very beautiful. Sora comments on how beautiful Reiko was and how somebody with those eyes could possibly be evil. She originally planned to suck up to student council members become their wife, then change the school to save the girls. She once asked the girls from the academy for help, but they told her to do it herself. Reiko then felt she had to work alone. After meeting Sora, Reiko broke down while telling her about the hardships she went through. She is one of the six “stars” and her weapon is a Flail.
Hiyo is a girl, who is madly in love with Sora after being rescued by her. Hiyo has an older sister, who always got into a fight with the boys resulting into a lot of numerous injuries. Reiko mentions Sora was a lot like Hiyo's sister, because she was reckless. Hiyo's weapon was mentioning not having one of the "stars". It is also shown that Hiyo might have stolen the battle records, making all the girls who was previously saved by Sora, getting tortured and injured by Tougyu.
L is the president of the student council. He is said to be cruel and cold-hearted. He also has the persona of Karin. He is physically characterized by his mask or when he is Karin, his eye-patch. He possesses one of the “stars”. It is unknown why he decides to help out Sora.
X is the first girl whose weapon is used by Sora. She wears a mask with a flower ornament and has long golden hair. She is a double agent who helps both L and Sora. In chapter 12.5, it is revealed that X is actually Shoujou, who cross-dressed to help L. It is unknown whether L asked him to do this or not. X's weapon is a blade that appears to be made of an extreme energy and is the most powerful weapon seen thus far.
Sumita is the vice-president of the student council. He wears a pair of black glasses. He does appear to have a kind side, as is demonstrated when he gets Tougyu to release Reiko.
Mitarai is a member of the student council. He appears to be gay and is madly in love with L.
Shoujou is a member of the student council. He is childish, and wants to be some help to L. He is revealed cross-dressing as X.
Kuchinawa is a member of the student council. He is always with El.
Kwatsu is a member of the student council. He is all talk and no power.
Kajiwara is a member of the student council. He is the first enemy, that Sora has defeated. He seems to have lost several times to Sora.
Tougyu is a member of the student council. He is insane and has destroyed many girls. He once had the ownership of Reiko and has tortured her badly before Sora rescued her.
Akane is one of Sora's allies. He seems to have some feelings for her. Wore a pair of glasses to 'hide', as Karin put it, but has now gotten rid of them, declaring that he's done hiding. Rather kind, if physically weak.
Exaclan is a virtual game in which male players possess females, who contain weapons. To use the weapons, the male players put on their gloves and remove the weapon from the girl's chest. A battle is held between two players and goes until one player or his girl faints, or he admits defeat. Despite being a virtual game, with no blood or the like, the players and weapons (girls) still feel pain. The player that wins the battle is given possession of the weapon of the loser.
The game is also set up so that the weapons can only be harassed by their own possessor. Should another person try to harass a possessed weapon, a penalty will kick in. For fifteen minutes, a headache will effect the weapon, the harasser, and the owner of the weapon. The second stage, which also lasts fifteen minutes, a greater headache effects the weapon, the harasser, and the owner. At the end of the thirty total minutes of “warning”, if the harasser does not stop or the owner does not rescue or release the weapon, the final punishment will be activated.
To win the game, one must collect all six “stars”. The stars are weapons that, when used, show a symbol. Sora has three stars, El has one, and two are hidden, or unknown.