This series is based on the games Valkyrie Drive: Bhikkhuni and Valkyrie Drive: Siren. The synopsis and trailer for the series is after the break.

The “beautiful girl sexy battle action” anime is set on five artificial islands. Mamori is a “mermaid” transferred to one of those islands. When Mamori is attacked, a newly transferred girl named Mirei saves her. The enemy doesn’t stop, however, and the two are soon cornered. Just when they think all hope is lost, Mirei kisses Mamori, and Mamori turns into a sword. Mirei then wields the sword and launches a counterattack against their enemies. (courtesy of ANN)

~^.^

Photo Credit: Valkyrie Drive: Mermaid, Arms Corporation