"Aggretsuko" centers on Retsuko, a 25-year-old red panda working in the accounting department of a Japanese trading firm. Her daily life is marked by the monotony and frustrations of office work, including demanding superiors, tedious tasks, and workplace politics. To cope with her stress, Retsuko secretly indulges in death metal karaoke, using the aggressive music as an outlet for her pent-up emotions. This duality—her outwardly polite and reserved demeanor contrasted with her inner rage—forms the core of her character.

The series explores Retsuko’s struggles with societal expectations, particularly as a young woman navigating a male-dominated workplace. Her boss, Director Ton, is a chauvinistic boar who frequently belittles her, while her colleagues, such as the gossipy fennec fox Fenneko and the laid-back hyena Haida, provide varying degrees of support and camaraderie. Haida, in particular, harbors unspoken feelings for Retsuko, adding a layer of romantic tension to the narrative.

As the story progresses, Retsuko faces challenges beyond her professional life, including societal pressures to marry, financial instability, and the search for personal fulfillment. Her journey involves exploring alternative career paths, such as pursuing a music career or starting her own business, though these endeavors often come with their own set of obstacles. The series also delves into her relationships with family and friends, highlighting her growth as she learns to assert herself and confront her anxieties.

Themes of self-discovery, resilience, and the balancing of personal and professional life are central to the narrative. Retsuko’s experiences resonate with many viewers, as they reflect the universal struggles of modern adulthood. The series blends humor and relatability with moments of introspection, creating a compelling portrayal of a young woman navigating the complexities of contemporary society.