"Neko ni Naritai Tamagawa-kun" centers on Tamagawa, a high school student who harbors a peculiar wish: to transform into a cat. This desire stems from his admiration for cats' carefree and independent lifestyles, which starkly contrasts with his own struggles with social anxiety and self-doubt. Tamagawa's fascination with feline behavior leads him to observe and mimic cats, often resulting in humorous and awkward situations as he navigates his daily life.

The narrative explores Tamagawa's interactions with his classmates, particularly his childhood friend, Yuki, who is both supportive and perplexed by his unusual aspiration. Yuki serves as a grounding presence, often challenging Tamagawa's eccentricities while encouraging him to embrace his individuality. Another key character is Rina, a classmate who shares Tamagawa's love for cats and becomes an unexpected ally in his quest to understand and embody feline traits.

As the story progresses, Tamagawa's journey takes on a more introspective tone, delving into themes of identity, self-acceptance, and the complexities of human relationships. His attempts to become a cat serve as a metaphor for his desire to escape societal pressures and find a sense of belonging. The series balances lighthearted comedy with moments of emotional depth, creating a narrative that resonates with viewers on multiple levels.

The plot unfolds through a series of episodic encounters, each highlighting Tamagawa's growth and the evolving dynamics between the characters. Whether he is trying to master the art of napping like a cat or navigating the challenges of school life, Tamagawa's experiences are both relatable and endearing. The series ultimately portrays a heartfelt exploration of individuality and the universal longing for connection, wrapped in a whimsical premise that captures the charm of its central character's unique perspective.