The girls of 765 Production Studio are eagerly preparing for the International Music Festival on Vacation Island. Coupled with an amusement park and a high-class resort, the festival promises several days of fun for everyone. That is, until their producer announces that they only have enough room for one unit to participate. In three different scenarios where everyone is split into three groups, one of the three is chosen to partake in the International Music Festival, where they are treated to a three-day vacation before starring in the festival's concert. From the moment they step off the boat until the main event, each group of girls experiences the festival in their own way, excited to take part in the highly anticipated performance.

The story is set in the year 311 of the Orbital Calendar, when humanity has migrated to countless colony clusters in space. A space colony girl named Akiha Shishidou encounters a malevolent artificial intelligence named Leopard that has been installed on a colony. Akiha is joined by an Inter-Colony Police officer named Itsuki Kannagi, a taciturn young girl named Honoka Kawai, and a robot named Imoko Imo-chan Shishidou. (Source: AniDB)

Naoko-san is an alien from the planet Yuri, who is plotting to conquer the Earth by yurifying it. Misuzu is a junior high girl and is always troubled by Naoko-san, who lives on the roof of her house. They hear rumors that a molester is wandering around in the area, so they decide to investigate.

Kazuki Yoshino and Yuuya Niyodo are idols who make up the duo ZINGS. While Kazuki gives his all in every performance, Yuuya views the job as just another means of making money. Yuuya's apathetic attitude toward the fans and inability to take his job seriously causes his manager to give him an ultimatum: unless he starts putting in more effort, he will be fired. Backstage, Yuuya meets Asahi Mogami, an idol dressed in a colorful costume. Asahi would have had a bright future ahead of her—had she not died a year prior. Even as a ghost, Asahi wants nothing more than to perform for fans again. When she finds out that Yuuya does not hold the same passion for the idol life that she once did, she is overcome by a fit of rage and demands that he let her take his place. In a strange twist, Yuuya wakes up to find that Asahi has possessed him and can do what he is too lazy to do himself. With Asahi performing for him, Yuuya thinks he has a ticket to an easy idol life. However, Asahi has other plans. Though she is no longer alive, she wishes for Yuuya to find the ambition that she still has. Together, she wants them to become the best idol the world has ever seen. But can an unmotivated man like Yuuya ever care about anything besides money?