Humans have designed countless worlds all born from the unique imagination of its creator. Souta Mizushino may be a highschool student who aspires to be such a creator by writing and illustrating his own light novel. One day, while watching anime for inspiration, he’s briefly transported into a fierce fight scene. When he returns to the important world, he realizes something is amiss: the anime’s headstrong heroine, Selesia Yupitilia, has somehow returned with him.
Before long, other fictional characters appear within the world, carrying the hopes and scars of their home. A princely knight, a magical girl, a ruthless brawler, and lots of others now crowd the streets of Japan. However, the foremost mysterious one may be a woman fully military regalia, dubbed “Gunpuku no Himegimi,” who knows much more than she should about the creators’ world. Despite this, nobody knows her true name or the planet she is from.