"Neko-ane" centers on the life of Aoi, a high school student who unexpectedly becomes the guardian of her younger half-sister, Neneko, after their parents pass away. Neneko, a reserved and enigmatic girl, harbors a peculiar secret: she possesses cat-like traits, including ears and a tail, which she hides from the world. The story explores their evolving relationship as Aoi adjusts to her new role as a caretaker while navigating the challenges of school, work, and personal growth.

The narrative delves into themes of family, responsibility, and acceptance as Aoi learns to balance her own aspirations with the demands of raising Neneko. Neneko’s feline characteristics are not merely superficial; they influence her behavior, making her more sensitive, agile, and prone to instinctual reactions. This dynamic creates both comedic and heartfelt moments as Aoi strives to protect her sister from societal scrutiny while helping her adapt to human life.

Secondary characters, such as Aoi’s classmates and coworkers, add depth to the story, providing support and occasionally complicating the sisters’ lives. The manga also introduces elements of mystery surrounding Neneko’s origins, hinting at a larger backstory that gradually unfolds as the series progresses. The interplay between slice-of-life moments and the underlying intrigue keeps the narrative engaging, blending everyday struggles with subtle supernatural undertones.

Aoi’s determination to provide a stable environment for Neneko drives much of the plot, showcasing her resilience and compassion. Meanwhile, Neneko’s gradual opening up to the world around her highlights themes of trust and self-discovery. The series balances lighthearted humor with emotional depth, creating a story that resonates with readers through its exploration of familial bonds and the challenges of unconventional circumstances.