The Tale of Johnny Town-Mouse" by Beatrix Potter tells the story of two mice, a country mouse named Timmy Willie and a city mouse named Johnny Town-Mouse, who trade places for a visit. The story contrasts the two different lifestyles and cultures of these two mice. Timmy Willie is used to a simple life in the country, while Johnny Town-Mouse is used to the finer things in life in the city.

When Johnny Town-Mouse invites Timmy Willie to visit him in the city, Timmy Willie is fascinated by the excitement and novelty of city life, but he finds it overwhelming and dangerous, especially when he encounters a cat and narrowly escapes a trap. On the other hand, when Timmy Willie invites Johnny Town-Mouse to visit him in the country, Johnny Town-Mouse finds the simplicity and lack of refinement difficult to adapt to, and he longs for the comforts and luxuries of city life.

The story teaches valuable lessons about hospitality, manners, kindness, sharing, adaptation, contrast, cultural differences, and the importance of home and familiarity. The book also highlights the themes of friendship, diversity, acceptance, communication, compromise, and empathy. The story is told with charming illustrations and whimsical language, making it a beloved classic of children's literature.