In 2019, a rift to another dimension suddenly opens in the skies above, revealing a "turnabout" alternate world called "Shinkoku Nippon." This parallel version of Japan maintained its militarism and remains stuck in the Showa era. Shinkoku Nippon invades our Japan with its "Genmu" gas weapons and giant humanoid "Garan" weapons. The invaders immediately take over our government and all but conquer Japan. As a result, our Japan never ushers in the Reiwa era. A decade later, our Japan has been revamped as Genkoku Nippon, a puppet state of Shinkoku Nippon. Under harsh censorship, the once thriving manga, anime, idol, and similar sub-cultures have completely died off...or so it seemed.

The United Earth Sphere Alliance is a powerful military organization that has ruled over Earth and space colonies with an iron fist for several decades. When the colonies proclaimed their opposition to this, their leader was assassinated. Now, in the year After Colony 195, bitter colonial rebels have launched "Operation Meteor," sending five powerful mobile suits to Earth for vengeance. Built out of virtually indestructible material called Gundanium Alloy, these "Gundams" begin an assault against the Alliance and its sub organization OZ. One Gundam, whose pilot has taken the name of the slain colony leader Heero Yuy, is forced to make a crash landing into the ocean after an atmospheric battle against OZ's ace pilot Zechs Marquise. Upon coming ashore, he is found by Relena Peacecraft, daughter of a peace-seeking politician, who witnesses Heero's descent to Earth. Although neither of them realize it yet, this encounter will have a profound impact on both their lives, as well as those on Earth and in space colonies. [Written by MAL Rewrite]

Saving the world... by fishing? Yuki Sanada has always felt like a fish out of water. Socially awkward and anxious, he struggles to fit in with his surroundings and moves from town to town with his grandma. As he and his grandma settle into the charming seaside town of Enoshima, Yuki hopes for a fresh start. However, his reputation at school is jeopardized by the arrival of fellow transfer student Haru. The eccentric Haru immediately makes a splash, wildly claiming to be an alien and declaring that Yuki is his friend. Pairing the reluctant Yuki with their classmate and fishing talent, Natsuki Usami, he tasks both of them with the absurd mission of saving the world from a mysterious threat in the ocean. Mischief and hijinks ensue, as these three embark on a whimsical adventure filled with laughs, heart, and self-discovery!