The alleged assault happened at last year’s Sanfermines bull run in Pamplona.
The 18-year-old victim gave her statement to the court today after arriving at the Pamplona Palace of Justice at 9:30 am.
The trial is being conducted in closed chambers to protect her identity.
Over the next few days, some fifty people will testify to the court, including police, witnesses and psychologists and forensic experts.
The five defendants have entered a plea of not guilty of sexual assault, although one has admitted stealing the victim’s phone.
The five young Sevillians, who are in prison, are charged with crimes of sexual assault and violent robbery.
The Prosecutor’s Office is seeking 22 years and 10 months in prison, as well as €100,000 in damages.
The defendants claim the sex was consensual and are seeking a not guilty verdict.
The trial is scheduled to run until the November 24.