Fifty-year-old Boris, balding and big-bellied, is madly in love with the young and beautiful Cezar. But Boris was born from Cezar's flank and is the size of a mouse. He leads a clandestine life entirely devoted to he who is both his progenitor and the object of his affection. Everything shifts dramatically the day when Cezar, who is unaware of Boris's existence, brings a woman back to their love nest.