Based on

Movies like Waterbomb for the Fat Tomcat (2004)

The parents have gone away, so the two sisters - Marta and Linda - need someone to take care of them. Their dictatorial spinster aunt Una, who desperately wants to get married, arrives to take on this job. Marta really wants a puppy, but her plan is ruined, as her aunt has a strong dislike for dogs. So, the relationship between the girls and Una becomes really tense. Until the perfect plan of the sisters emerges - to get rid of the aunt by helping her to get married.