Young Arika Yumemiya travels to the Kingdom of Windbloom in order to become an Otome. She soon becomes acquainted with Garderobe student Nina, Nina's foster father Sergay, and the rebellious princess Mashiro.

Deeply impressed after witnessing the power of Meister Otome Shizuru Viola, Arika is more determined than ever to become a real Otome and attend the school of Garderobe. However, before her wish can become reality, certain conditions must be met.

In order to acquire permission to attend the Otome school of Garderobe, unexperienced Arika must face Nina in an exhibition battle during the coronation ceremony of Mashiro.

After a safe conclusion to the crisis of the previous episode, Arika is admitted to Garderobe and receives some important lessons on the way. She earns some new friends as well as some new enemies.

Arika's studentship is put in jeopardy when her uniform appears in a store. To prove that she didn't sell the uniform, Arika places her trust in her new friends to uncover the true culprit.

Upperclassman Shiho's jealousy towards Nina reaches catastrophic heights, as she decides to sabotage the school's swimming pool during sports class. Once again, it's up to Arika and her friends to clean up the mess.

While helping with the reconstruction of the royal palace, Arika hears a rumor about Mashiro. Arika and Mashiro find a mysterious machine beneath the castle.

After making a contract with Mashiro in the climax of the previous episode, Arika is now responsible for finding a way to cancel it. In order to learn more, Arika and her friends break into the Mausoleum of Garderobe.

As a part of the Otome training, Arika's Coral class begins a 100 km hiking trip through Aries. With randomly chosen pairs, the students enter into wilderness, when things start to go wrong for Arika and her partner Erstin.

Garderobe, Aries, Windbloom, and Artai move to rescue the two lost Coral students, as a mysterious group, Aswad, moves through the area.

Nina and Arika are sent to escort Mashiro to a meeting with royal guests from a neighbouring country. To avoid an international conflict when Mashiro runs away, Windbloom comes up with a hasty substitute.

Arika impersonates the missing Mashiro and meets the foreign prince Takumi, while Nina pretends to be Arika. Meanwhile, Mashiro takes the name of Nina and ends up in the slums of Windbloom, where she meets a foreign boy.

Arika realizes she has developed feelings for Sergay, and is having hard time trying to choose between the fate of an Otome and finding a love of her life. Elsewhere, two Meister Otomes from different countries battle against each other.

Arika's friends become concerned over her strange behavior. Meanwhile, Shizuru investigates the boiling Otome conflict between the two countries of Romulus and Remus.

Sergay rescues Arika from a dangerous situation, allowing her a chance to act on her feelings. Arika later talks to a similarly distressed Mashiro.

Arika, Nina and Erstin all promise to become Meister Otomes together. However, Nagi de Artai and Schwarz begin a coup against Windbloom and Garderobe.

With hostile forces invading the capital of Windbloom, all Otomes are summoned into battle. But an enemy plan causes the source of the Otome technology to shut down, and Arika finds herself fighting against her dearest friends.

Three days after the disastrous raid against Windbloom, Mashiro is forced to join refugees fleeing from their homeland. Nina now serves as the Meister Otome of Nagi. Getting to know her exiled people better, Mashiro learns the painful truth about her leadership qualities.

Mashiro wakes up in the village of Aswad and is reunited with Arika. Elsewhere, Natsuki and Nao make their way toward the Republic of Aries in order to request help.

Being distanced from her old friends, Nina is drawn ever more closer to her foster-father Sergay. Natsuki's request for aid is turned down in Aries, so she's forced to seek help from Cardair, where the king has just sent his Otome to claim valuable data from the village of Aswad.

Nagi discovers that the true heir to the throne might be Nina. Mashiro feels compassion for her exiled people and asks Aswad to take them in. Sergay forms a plan to capture Mashiro with the assistance of the Valkyrie unit.

Aswad attacks Cardair in retribution for their betrayal. Back at the village, Sergay and the Valkyries arrive to take Mashiro and Arika by force. Meanwhile, Nagi has Nina activate the true power of the Harmonium.

Arika, Mashiro and Miyu end up in the Black Valley, where they encounter Mai and Mikoto the Cat Goddess. Natsuki and Nao later join them.

While plans to liberate Windbloom are underway, Sergay puts his life on the line in order to protect Nina and destroy the source of the power of the Slaves and Valkyries.

Nina operates the Harmonium in order to save the fatally wounded Sergay. Meanwhile, Operation Liberate Windbloom is put into full action, with rival armies squaring off against each other and the Otome attempting to gain their powers back.

The Otomes face off against Nagi and the power of the Harmonium, and Arika comes into conflict with Nina in a final battle.