The story of Bento Swap in Crayon Shin-chan takes place in episode 142 of the first season. In this episode, Shin and his friends are enjoying a bento lunch at kindergarten together. Usually, Shin's bento is carefully prepared by his mom, Misae, but on this day, Shin is bored with his bento and longs to try others'. So, he comes up with an idea to exchange his bento, which gets a positive response from the other kids, who all exchange their own bento with Xiao Xin.

During the bento exchange, Xiaoxin tastes a variety of food, including sushi, fried chicken and cakes, to his delight. However, when he eats the last of his friend's bento, he realizes that it is a healthy bento filled with vegetables, making him wonder about his choice.

This episode shows the friendship and interaction between Xiaoxin and his friends through the bento exchange episode, and also conveys the concept of healthy eating by cherishing food and not being picky about what you eat.