Yuuko Konagai, a typical high school student, is shy and socially awkward. As a result, aside from receiving subpar marks, she has few friends in her class. However, after a tiring day at school, she returns to her much-anticipated haven—home with her kitties Maa, Shi, and Ro! With their distinct personalities, the three have human-like bodies and the capacity to talk and converse. Every day, the cute group looks forward to their owner's return to provide her with much-needed company. Nyanko Days depicts Yuuko and her kitties as they brighten each moment and create new acquaintances as the days pass.