Martín, a 12-year-old boy from Tucumán, introduces his friends: Pepe the Agüará Guazú, a thin tall brown-haired brown-eyed rodent; Rosita the Tatú Carreta, a small brown-shelled brown-bodied brown-eyed armadillo with a long nose; Aurora the Lobito de Río, a long thin dark-haired short-legged long-tailed creature; and Nachito the Tapir, a big plump grey-haired brown-eyed animal with small ears. The friends declare they are best friends. The cast and creator are listed at the end.