Aspiring light novel author Yuu Nagami regularly enters writing competitions but has yet to win a single one. Despite his recurring failures, he remains steadfast in his resolve to become a better writer. When he takes a look at the list of winning authors in the latest contest he joined, he notices that someone named Chikai Towano dominated the competition. He soon discovers that behind the pen name is his sister Suzuka—the last person he can imagine being an author. Suzuka cannot reveal to anyone that she is Chikai Towano and requests her brother to take her place. Yuu agrees with one condition: he will continue posing as Chikai Towano for his sister until he publishes his own book. Until that happens, Yuu uses his new identity as an opportunity to improve his writing skills and meet fellow authors and new acquaintances along the way.

In Martian colony Fourth Tokyo lies a classroom of Kirishina Corporation's brightest minds spearheading aerospace development: A-TEC, led by genius engineer Kaito Sera, eagerly anticipating the arrival of their newest member. It soon becomes clear, however, that the transfer student is hardly ordinary—Nagisa Kiryuu, newly appointed chief of A-TEC and the younger brother of the corporation's CEO, is sent to shut the program down. To keep the classroom alive, Kaito and his students desperately work to develop a successor to their most powerful rocket, the X-2; meanwhile, Nagisa climbs the corporate ladder in pursuit of his own mission. In spite of this, their separate battles soon reveal that much more is going on in Kirishina Corporation than meets the eye. Classroom☆Crisis follows Kaito and Nagisa, as well as Kaito's younger sister Mizuki and A-TEC's test pilot Iris Shirasaki, in a story of intrigue, political warfare, and, against all odds, romance. As Nagisa and A-TEC are dragged further and further into Kirishina Corporation's conspiracies, friendships grow and pasts are unveiled as they fight to avert their classroom crisis.

After Brook questions the origin of the Mini Merry name, Usopp and Chopper Tony Tony recall the adventures of the Straw Hat Crew's beloved ship, friend, and crew member—the Going Merry. Ussop abandons the crew for a fight over the Going Merry while Robin Nico leaves with the government's top assassin group, CP9. In order to bring the crew back together, Monkey D. Luffy and the remaining Straw Hats follow Robin to rescue her from the claws of the World Government.

Takumi no Shitamachi Kassen Following the end of the exhausting training camp, brothers Takumi and Isami Aldini spend their holiday sightseeing Tokyo Tower and its surroundings. While learning about the local culture and tasting various dishes, the two encounter Megumi Tadokoro, Ryouko Sakaki, and Yuuki Yoshino, who all happened to be touring the area as well. The group decides to have lunch together at a traditional Japanese restaurant—where an unexpected food duel is set to take place. Natsuyasumi no Erina Tootsuki students are hard at work experimenting with dishes for the Autumn Elections during the summer break; but for Erina Nakiri, her preparations for the event are already complete. Just as she dwells on what to do with her free time, she receives an invitation to the public pool from her cousin Alice. Despite her initial hesitation, Erina takes the opportunity to broaden her horizons and explore what this seemingly ordinary summer activity has to offer. Meanwhile, the members of the Polar Star Dormitory kick off a small party at a nearby lake to cool off and enjoy themselves before the Autumn Elections.