Anime event takes place at the island mermaid, where the main role is played by females, who are carriers of a strange, so-called "gun virus" — A. These girls are divided into two classes, depending on their abilities: exteri, transforming into a weapon during sexual excitement, and the liberator, able to use weapons in the form of exterol. The metamorphosis is done through a process known as "Drive", which can only be used fit together the