Half-Sister
Demi-sœur (original)
When Nénette (Josiane Balasko) discovers the identity of her father in a letter, she quickly goes off in search of him. But instead of finding her father, she is met by her half-brother, Paul (Michel Blanc). Paul, a bitter man who gave up his dream to take over his father’s pharmacy business, is less than thrilled at the arrival of his ‘embarrassing’ half-sister. After refusing to take her in, he soon gets a taste of his own medicine. Under the influence of a potent drug, for one day Paul is generous, happy and sensitive. The next morning, however, once the drug has worn off, his nasty side comes back...
Starring Josiane Balasko, Michel Blanc, Brigitte Roüan, Françoise Lépine, Christine Murillo, Grégoire Baujat, Jean-Yves Chatelais, Stéphan Wojtowicz, Chantal Banlier, Sarah Suco
It's a comedy and drama movie, and has a rating of 5.5 out of 10 from Imdb which is fairly okay for this kind of movie.
Watch it here
Not found streaming from Argentina.