Lagrange: The Flower of Rin-ne

Several months have passed since Lan and Muginami left Earth. Now in her final year of high school, Madoka spends most of her days thinking about her friends, when Lan suddenly returns to Kamogawa City.

Rinne no Lagrange OVA.

In an unplanned field trip, Riko is transported to an alternate Japan where metal-based life forms known as Mimesis ravage the world. Only girls equipped with LBX armored weaponry can stand up to this scourge. Joined by four other displaced young women, Riko will have to adapt to save humanity. The hope of a planet now rests on these heavy metal soldiers who desire one wish—to return home again!

Rin Namiki's greatest ambition is to follow in her late mother's footsteps and compete in Kandagawa Jet Racing, where teams of girls on jet skis race while firing high-powered water guns to slow their competitors' jets (and blow off their clothing!). But since there's no jet racing in Rin's remote fishing village, that means moving, all by herself, to a girls' school in faraway Tokyo! Meanwhile, Misa Aoi dreamed of becoming a great player, but those ambitions floundered until Rin transferred to her school, displaying astonishing skill for a newcomer. Is it fate? Now they "only" have to resurrect their school's Jet Riding Club, endure brutal training, and face some seriously skilled rivals… but even the toughest tasks are easier when you're doing something you love with someone who's quickly becoming far more than just a friend!