Valkyrie Drive: Mermaid

Mamori Tokonome, a girl who was diagnosed with an irregularity in her body, is captured by agents and taken to a remote island.

Mirei and Mamori defeat Saejima, but they are restrained and locked in a disciplinary room. Mamori now needs to prepare for a mysterious ceremony known as the Wedding.

After escaping the clutches of Wärter, Mamori and Mirei learn the nature of the militant female-only group and find a town run by Torino Kazumi that's free from its rule.

Kasumi, Charlotte and Wärter's forces move to take Mirei into custody, but the Lady Lady duo intervene. Another new participant halts the fight that ensues.

Kasumi leaves the castle to look into a strange Extra reading in the forest. She finds Mirei and Mamori, the group soon bumping into a girl named Nimi Minimi who has run away from the castle and can't stop growing.

Meifeng tries to steal more goods from Veste and makes money from gambling. Seeking to place some bets, she arranges for Mirei to enter a beauty pageant being held at the Mermaid Festival.