Matteo Cillario is such a frugal lawyer, he avoids having children because he is convinced they are too costly. One morning he discovers that is best friend is about to become his worst client: Mimì Rendano has held up a bank and taken people hostage by threatening them with a gun and claiming to have a briefcase full of explosives. Matteo knows that Mimi is the kindest man on earth, and this is why he wants to tell his story. Mimì is a thirty year old dreamer who has always been in love with Ketty, although he hasn't seen her since they left school. When he meets up again with his childhood friend Giovanni, to make plans for starting a business together, he will discover that Giovanni has married the woman of his dreams. Eventhough Mimì hides the fact that he is still in love with Ketty, this doesn't help matters since he continues to spend all of his time with this happy family ,even sharing in the birth of their daughter, Maria Assunta. After Giovanni dies suddenly from an incurable illness, Mimi will discreetly try and help Ketty realize her lifelong dream of opening up her own boutique, along with making sure her daughter is well looked after,so that he will eventually make his way into Ketty's heart. Just when it seems like his dream is about to come true, everything suddenly falls apart. Thanks to a misunderstanding at the bank, his bank loan is denied. Mimi afraid of losing Ketty, desperate to cover things up, writes Ketty a number of blank checks. When Ketty finds out the truth, she accuses Mimi of being out of his mind and never wants to speak to him again. Mimi feeling his world crumble around him, knows that it was only his love for Ketty that made him commit such a desperate act, and cannot believe that because of money his own existence would merely vanish. His desperate attempt at the bank will lead to a series of hilarious situations that will create all kinds of havoc. Thanks to the help of his friend and lawyer Matteo, he will end up being put under house arrest at Ketty's home. It will not turn out to be anything like he had imagined.......