Kouichi Sanada and Kazuki Aihara's childhood friend Mao Mizusawa has returned after living in France for a couple of years. Kouichi is surprised to learn that, since her parents are remaining overseas for the time being, his mother has agreed to let Mao stay with them. The three friends help each other deal with the ups and downs of high school romance.

In a dystopian future where Japan's political organization has crumbled after the Great Tokyo War, Japan is broken up into 10 independent nations, with each nation controlled by a gang led by a "Best," a human-proclaimed prophet with destructive superpowers. Nozomi Moritomo is a "Rest"—a normal girl that has just started out as a rookie in the local gang. She wants to help the Best Masami Utoku, her childhood friend and role model, in the ongoing territorial dispute. When Masami becomes severely injured and unable to fight, Nozomi decides to go on a mission to complete the requests sent to Masami from all over Japan. Along the way, she meets Yukina Kosaka, a shy girl with no sense of direction; Ai Hibiki, an upbeat girl who loves eating; and Chiaya Misono, a quiet and mysterious girl that wears a gas mask. Together, the four girls travel all over the country on their motorcycles while getting involved in territorial wars, disagreements, and even suspicious conspiracies. [Written by MAL Rewrite]

Maiku Kamishiro's past has always been somewhat of a mystery to him. The only clue he has to who his family might be is an old photograph showing two young children, a boy and a girl, playing in a small pool outside of a blue house. In an attempt to find his family, he moves to this blue house and begins working as a programmer. He's living a comfortable life until the day two very different girls show up at his door, both in possession of the same photograph, and both claiming to be his twin. With no way to prove who is a relative and who is a stranger, Maiku allows both girls to move in with him until they know for sure. 

(Source: ANN)

The compilation film will recap the anime's 59 episodes from seasons one to three.