The story centers around a spirited high school girl named Marika. She keeps herself busy with the space yacht club and her part-time job at a high-class retro café. One day, two strangers suddenly appear and claim to be subordinates of her dead father. They demand that she assume command of the space pirate ship Bentenmaru. A privateer ship's compact was made during a war of independence a century ago, and according to that compact, the ship must be inherited by the captain's next direct descendant. Marika finds herself embarking on a new life as a space pirate.

[Source: MyAnimeList]

It’s spring break for Marika, captain of the Bentenmaru, but she isn’t having any fun in the sun. A rash of subspace accidents is putting pirates out of work, but luckily Jenny Dolittle has a mission for Marika. She asks her to “raid” a Fairy Jane ship called Begin the Beguine, but there’s more to this performance than meets the eye, and soon Marika meets Kanata Mugen — a boy with a startling request for the captain of the Bentenmaru!

[Source: Sentai Filmworks]