A casual punch of Miguel "El Tarta" during a football game injures Molina, Spain boxing champion. This incident changed the life of Miguel. Manolo, will use the incident to convince Miguel that it is a real potential champion and must engage in boxing. his will take care of looking for an equity partner, Mr. Roman, and an unscrupulous manager, Peter Rodriguez. With the nickname "El Tigre de Chamberí" Miguel is thrown into the ring, fighting with more enthusiasm than technique. Their main concern is to attract the attention of Marisa, daughter of Mr. Roman, and that is deeply in love.