High school girl duo Popuko and Pipimi are back and more unhinged than ever after their initial efforts to create a full-fledged anime production were met with a great reception. With no regard for their audience, they continue to live their reckless everyday lives consisting of comedy skits and parodies of epic proportions. No one is immune to the effects of their antics—including hapless live actor Shouta Aoi, who is on the run and stuck trying to be a hero in the wrong series.

Thanks to Professor Yuuko Kouzuki's technology and Kasumi Yashiro's psychic powers, Cadet Takeru Shirogane travels back to his original world. With no time to lose, Takeru aims to enlist Yuuko's help in his world to complete the Alternative IV project—the last hope humanity has against the BETA, an alien species invading the planet. As the anti-BETA project nears completion, Takeru and other cadets graduate from the Yokohama pilot training academy. However, during a test of the new operating system for the Tactical Surface Fighters—the giant combat suits used by humanity against their adversary—the BETA ambush Takeru and his team. Barely escaping with his life, Takeru is left traumatized after witnessing the cruel death of one of his close friends. Losing his will to fight, Takeru flees back to the other world, where he experiences a similar tragedy. According to Yuuko's theory, people from parallel universes are bound to suffer the same fate. As a result, Takeru must overcome his trauma if he wants to protect the ones he holds dear.

Gaowei crossed in an airplane accident and appeared on the Loren continent as the ancestor of the Cecil family. In the face of the declining family, he re-expanded the territory, and in the face of class barriers, he used the wisdom of the people. But the crazy and stubborn cultists and the potential crisis of the magic tide are still there, how should Gaowei face the world that is about to usher in the end of the era...

While reminiscing about her journey so far, Aoi Yukimura finds herself eager to go mountaineering once more. A likely opportunity arises when Koharu Senjuin invites Aoi to check out the Mountaineering Club after school. As the head of the club, Koharu speaks enthusiastically of the activities she and the other members partake in, especially as they strive to reach the top in various competitions. Although impressed by the club's dedication to its goals, Aoi feels reluctant to join, preferring to learn and enjoy mountaineering at her own pace. Her experience during this brief visit, however, leaves her wondering why she climbs mountains in the first place. With the support of her friends, Aoi searches for the true motivation behind her hobby, all while continuing to train for the highly anticipated second trip to the summit of Mt. Fuji.