The king of Natra has fallen ill, leaving the only hope for his kingdom to his son, Prince Wein Salema Arbalest. Known to be capable and wise, he is the perfect candidate to become the prince regent. However, if the prince has anything to say about the matter, he would rather sell off the Kingdom of Natra to the highest bidder! Since he wields the authority of the throne, no one can stop Wein from auctioning off the country and using the profits to retire in comfort. All he needs to do is raise the value of the small kingdom to maximize his gains. But whether Wein's grand plan will succeed remains to be seen, as his wit often surpasses even his own expectations—much to the benefit of the oblivious citizens of Natra.

Amid the desolate remains of a once-thriving city, only the rumbling of a motorbike breaks the cold winter silence. Its riders, Chito and Yuuri, are the last survivors in the war-torn city. Scavenging old military sites for food and parts, the two girls explore the wastelands and speculate about the old world to pass the time. Chito and Yuuri each occasionally struggle with the looming solitude, but when they have each other, sharing the weight of being two of the last humans becomes a bit more bearable. Between Yuuri's clumsy excitement and Chito's calm composure, their dark days get a little brighter with shooting practice, new books, and snowball fights on the frozen battlefield. Among a scenery of barren landscapes and deserted buildings, Shoujo Shuumatsu Ryokou tells the uplifting tale of two girls and their quest to find hope in a bleak and dying world.

Middle school student Mirai Onozawa is dissatisfied with her family circumstances and, in a moment of frustration, wishes to tear everything apart. Unfortunately, these destructive thoughts seem to come true in the form of a magnitude 8.0 earthquake just a few moments later. When summer vacation begins, Mirai reluctantly takes her younger brother Yuuki to Odaiba, where a robot exhibition that he wanted to go to is being held. However, while they are in the exhibition center, the fury of a major earthquake shakes the Kanto region; helpless, both kids witness the devastating power of this natural disaster as it brings the city to its knees. In its aftermath, they stumble upon Mari Kusakabe, a motorcyclist and single mother who decides to help the young siblings. Aiming to return to their homes and reunite with their families, the group sets off on a long and hard journey through the decimated city.

Over three hundred years have passed since the Calamity War, the great conflict between Earth and its outer space colonies. Now Earth is ruled over by four economic blocs, and the military organization Gjallarhorn is responsible for keeping the peace. Mars, on the other hand, depends heavily on Earth's economy. Horrified by the appalling living conditions that Mars' inhabitants have to bear, Kudelia Aina Bernstein, a young aristocrat from the Chryse Autonomous Region, gets involved in the Red Planet's independence movement. She hires the services of a local company, Chryse Guard Security (CGS), to escort her on the journey to Earth to negotiate economic conditions with the earthly bloc that controls the region. The Third Army Division—consisting of Mikazuki Augus, Orga Itsuka, and many other child soldiers—are chosen to protect her. When Gjallarhorn attacks the CGS facilities to assassinate the young revolutionary threatening their interests, Orga and his comrades must not let the attackers accomplish their goal—in fact, Gjallarhorn's actions might turn out to be the unintentional catalyst that leads the children to be the forgers of their own destiny.