Necchi is a big, long cat whose main interests include napping, lazing about, and finding creative ways to demand attention from his human companion. Whether stretched out in a sunbeam or curled up inside an empty cardboard box, Necchi is never picky about where he chooses to lounge. Unlike more destructive felines, this sweet-natured cat never scratches furniture or knocks objects off shelves when displeased. Instead, he simply extends a single paw in refusal. He also possesses an intuitive sense for when his human needs comforting, offering cuddles at just the right moments.

The manga follows the daily life of Necchi and his owner in what appears to be an ordinary household setting, likely in contemporary Japan given the author. The narrative is structured as a slice-of-life comic featuring short, episodic vignettes rather than an overarching plot. Each chapter presumably showcases Necchi discovering new napping spots around the home, interacting with his human, or demonstrating his peculiar but endearing behavioral quirks. The original Japanese title is Acchi Kocchi Necchi.

The cast centers primarily on Necchi and his unnamed human owner. No other major recurring characters have been identified. The tone is warm, humorous, and observational, focusing on the quiet joys and gentle absurdities of sharing a home with a cat. As a josei demographic title, the comedy and slice-of-life elements are likely crafted to appeal to adult readers who appreciate leisurely, character-driven stories about everyday moments. The narrative does not appear to involve dramatic conflicts, antagonists, or serialized story arcs, instead offering a relaxing portrait of interspecies companionship.