Set in the year 2200, Japan has transformed into a nation dominated by cats due to a severe decline in the human birth rate. In this future society, felines have developed the ability to speak, learn, and hold jobs, seamlessly integrating into everyday life alongside the remaining human population. The story centers on Sora, an ordinary high school girl navigating this unusual world, and her own pet cat, Mugishima-san. Unlike a typical pet, Mugishima-san has a strong, argumentative personality and engages in constant, witty bickering with Sora over the mundane details of their daily routines. The series presents a calm and relaxed slice-of-life narrative, often categorized as iyashikei, which focuses on the simple, humorous interactions between the characters. Other residents of this world include Sora's friend Yume-chan, who owns a cat named Kinako, and a library committee member. The 12-episode series, with each installment running approximately two minutes, eschews a grand, overarching plot in favor of short, self-contained vignettes. Episodes typically follow Sora and Mugishima-san as they go about activities like reading, attending school, or simply spending time at home, all while the anime treats its extraordinary premise of a cat-ruled Japan with a casual, everyday normalcy. The narrative arcs are not dramatic or world-altering but are instead built around the gentle comedy of a stubborn teenager living with an equally stubborn, talking cat, ultimately offering a lighthearted and relaxing look at life in a future where cats have inherited the earth.