Quico and Doña Florinda are invited to a fancy party, and she insists to Quico to keep his clothes clean. However, when Chavo and Chilindrina are tired of listening to Quico mocking them, they vow to ruin his clean little sailor outfit.
Don Ramón washes his ties because he is searching for a job, however, he keeps washing them over and over again because the kids use them to play. Professor Jirafales gives Quico a puppy, and he baptizes it as 'Ramoncito'.
Now is forbidden to have animals in the neighborhood, but Quico gets a mouse and hides it in a paper bag. But everybody confuses the bag with the mouse with a bag of popcorn, a bag of sugar, and a bag with cheese, creating a big confusion.