It has been 50 years since mankind began its migration to the terraformed Mars, where they live in comfort due to advancements in AI. Carole lives in the metropolis of Alba City, working part-time by day and playing keyboard by night. Tuesday has run away from her home in Hershell City to escape the grip of her wealthy family, and instead hopes to pursue music with her acoustic guitar. After a fateful encounter, the two decide to perform music together. Up against the AI singers that dominate the music world, the two of them believe that together they can convey their feelings through their songs. Will hard work and luck be enough for the duo to create the biggest miracle that Mars has ever seen? [Written by MAL Rewrite]

After living together for three years, Misaki Takahashi and Akihiko "Usagi" Usami's relationship has been progressing smoothly. However, all great relationships have problems, and theirs is just beginning. With a new rival on the horizon, Usagi worries about Misaki's feelings towards him. Meanwhile, Ryuuichirou Isaka has always loved to intrude on Misaki and Usagi's love life, but his own love life hasn't been all smooth sailing—Isaka and his secretary Kaoru Asahina have been dating for a few years; however, Asahina prefers to keep their professional and private lives separate, often leading to troubled waters between them. As for Nowaki Kusama and Hiroki Kamijou, now that their careers are finally taking off, they hardly see each other anymore. With the time they spend together lessening, doubts and insecurities threaten to creep in between them. On the other hand, the 17-year age gap between Shinobu Takatsuki and You Miyagi has been a constant barrier in their relationship, but as they learn more about each other, their self-consciousness continues to fade. The beloved couples of Junjou Romantica, Junjou Egoist, and Junjou Terrorist are back again, this time with a new addition: Junjou Mistake!

Not much is notable about the lecherous Ataru Moroboshi, but his extraordinary bad luck sticks out like the horns in an alien's head. When Earth is threatened by a fleet of alien invaders known as the Oni, Ataru is selected to represent humanity in a duel against one of them. It's a stroke of rare luck for Ataru that the duel is in fact a game of tag, and that his opponent is Lum, daughter of the Oni's leader, who places her personal dignity above victory—as Ataru finds out by seizing Lum's bikini top and with it, victory. However, misfortune kicks in again when Lum mistakes Ataru's promise to marry his girlfriend, Shinobu Miyake, as the desire to wed Lum herself, and decides she rather likes the idea. Wielding her influence as an alien princess, she moves in with him. Forced to deal with the consequences of his womanizing ways, Ataru must balance his crumbling relationship with Shinobu while keeping Lum happy, all the while flirting with every woman he meets.

Humans have designed countless worlds—each one born from the unique imagination of its creator. Souta Mizushino is a high school student who aspires to be such a creator by writing and illustrating his own light novel. One day, while watching anime for inspiration, he is briefly transported into a fierce fight scene. When he returns to the real world, he realizes something is amiss: the anime's headstrong heroine, Selesia Yupitilia, has somehow returned with him. Before long, other fictional characters appear in the world, carrying the hopes and scars of their home. A princely knight, a magical girl, a ruthless brawler, and many others now crowd the streets of Japan. However, the most mysterious one is a woman in full military regalia, dubbed "Gunpuku no Himegimi," who knows far more than she should about the creators' world. Despite this, no one knows her true name or the world she is from. Meanwhile, Souta and Selesia work together with Meteora Österreich, a calm and composed librarian NPC, to uncover the meaning behind these unnatural events. With powerful forces at play, the once clear line between reality and imagination continues to blur, leading to a fateful meeting between creators and those they created. [Written by MAL Rewrite]