Valkyrie Drive: Mermaid is a tV series anime that premiered in fall 2015, produced by ARMS.

About the production: the story comes from an original script, there are 12 episodes of about 23 minutes and its current status is "finished".

Its main genres are action, ecchi, fantasy, romance and sci-fi, with themes such as Henshin, Nudity, Primarily Female Cast and Yuri.

On AniList, Valkyrie Drive: Mermaid has an average score of 55%, an average score, and appears on 40,675 users' lists.

After adorable “mermaid” Mamori is transferred to one of five artificial islands, she’s cornered, attacked and eventually saved by another beautiful transfer named Mirei. Unfortunately, even after the girl intervenes, Mamori’s attackers refuse to let up. Just when they think all hope is lost, Mirei and Mamori share a passionate kiss that turns the little “mermaid” into a powerful sword. (Source: FUNimation)

Official synopsis from AniList.