Ostwind (2014)

14-year-old Mika cannot seem to stay out of trouble, so her parents send her to spend the summer with her grandmother, who runs a prestigious riding school and demands discipline from horses and students alike. Mika soon clashes with her grandmother until she discovers an untamed stallion, Windstorm, in the stables. The horse matches the girl in willfulness, and the two form a mystical bond that gives Mika confidence - and the chance to prove herself to her grandmother.