High school student Hodaka leaves his home on an isolated island and moves to Tokyo, but he immediately becomes broke. He lives his days in isolation, but finally finds a job as a writer for a shady occult magazine. After he starts his job, the weather has been rainy day after day. In a corner of the crowded and busy city, Hodaka meets a young woman named Hina. Due to certain circumstances, Hina and her younger brother live together, but have a cheerful and sturdy life. Hina also has a certain power: the power to stop the rain and clear the sky.
The story centers on the relationship between Hinako, who has moved to a coastal town upon entering university and Minato, a young firefighter with a strong sense of justice. Hinako loves surfing and while fearless on the sea, she's still uncertain about her future. Following a fire mishap in the town, Hinako and Minato encounter each other. As they spend more time surfing together, Hinako feels drawn to Minato, who dedicates himself to help others.
The story begins when Ao opens a package that arrives at her doorstep. Inside the package is Gourai, a Frame Arms Girl: a small robot capable of independent movement. Gourai is a newly-developed prototype: a Frame Arms Girl equipped with an "Artificial Self," an advanced AI that gives her a personality. Ao is the only one that has activated her. Gourai begins to gather both battle data and emotions, starting a day-to-day life with Ao, who knows nothing about Frame Arms Girls.
The story centers on Princess Vanilla, a princess in a land of ice cream, but who nevertheless is unable to create ice cream herself, no matter how much she practices every day. Finally fed up with her lack of ability, she flees her palace, and soon meets Anpanman and Kokin-chan. While traveling with them, she learns the reason why she can't create ice cream. Meanwhile, Baikinman attacks the land of ice cream while Princess Vanilla is missing.