Many long years ago in the land of OZ, a baby girl is born with skin of green, whom her parents name Marinette. Shortly after her sister, the weak Sabrina is born, confined to a wheelchair. They attend Shiz University, where Marinette develops an immediate hatred towards the school princess and her roommate, Chaloe, who also hates Marinette. During their time at school, Chaloe meets and falls in love with the transfer student, Adrien, who plans a ball for the students. Before at the ball, Chaloe sets up Sabrina with Kim, whom Chaloe rejected because of her love for Adrien, as well as gives Marinette a horrendous hat to wear. Despite everyone appalled by Marinette's presence at the party, Chaloe feels bad for how she treated Marinette when at Marinette's insistence Chaloe was allowed into the sorcery program. Chaloe and Marinette become friends, but Marinette begins to fall for Adrien when he helps her free a lion named Plagg that was to be a class experiment. Shortly after, Marinette is invited to meet the Wizard of Oz, and takes Chaloe, renaming herself Chloe. While there, they discover that the Wizard is responsible for poor treatment of the talking animals, to whom Marinette vows to free, but Chloe chooses to remain behind.

Years later, Chloe and Adrien are engaged, with Chloe as the royal sorcerer and Adrien as Captain of the Guard. They have been searching for Marinette for years to no avail, but she has been slightly successful in her protests. Marinette runs to hide with her family only to find out her father is dead and Sabrina is the cruel ruler of Munchkinland. In order to help her sister, Marinette gives Sabrina's shoes the ability to walk, but Kim still refuses her. Sabrina tries to use magic but fails, Marinette turning Kim into a man of tin to save him. Marinette flees.

Marinette meets with the Wizard, who agrees to free the monkeys she gave wings to in order to stop Marinette's protests. She then finds the Wizard kidnapped her old Professor Tikki, turning the creature into a dumb animal. Chloe and Adrien find Marinette as she is about to flee, when Adrien abandons Chloe and chooses Marinette. Heartbroken, Chloe tells the Wizard and his press secretary, Madame Mendeliev the best way to get to Marinette is through her sister.

Marinette and Adrien spend an intimate night together, when Marinette feels something is wrong with her sister. She orders Adrien to hide while she investigates. Marinette finds her sister dead, and Chloe giving the shoes to a young girl named Manon. The girls argue once Manon leaves, Marinette almost being captured by guards, when Adrien intervenes and sacrifices himself for her. Marinette, from the safety of a tower, casts a spell to save him, but feel as if it is all for naught.

Meanwhile, Manons companions rally the people of Oz to go after Marinette after kidnapping Manon. One being Kim, the tin man, and Plagg, the cowardly lion. Chloe goes to warn Marinette and insist she free Manon, but Marinette refuses, resigned to her fate, but glad for the time she had with Chloe. Marinette "dies" leaving behind her hat and an elixir Chloe recognizes to once belong to the wizard, who realizes he is Marinette's true biological father. Chloe banishes the Wizard and imprisons Mendeliev before addressing the people of Oz over Marinette's death. Back at the tower, the Scarecrow returns to find Marinette had survived and used a trap door, the Scarecrow revealing himself to be Adrien saved by her spell. They leave Oz together while Chloe grieves.

The summarization probably lacked, but if you've seen the Musical, you understand the gist.

Whose Who:

Elphaba - Marinette

Galinda/Glinda - Chaloe/Chloe

Nessarose - Sabrina

Fiero - Adrien

Wizard - Master Fu

Madame Morrible - Mendeliev

Boch - Kim

Doctor Dillamond - Tikki (any Kwami will do)

Cowardly Lion - Plagg

Chistry - Wayzz