Seventeen-year-old Raffi Cappello is in a bind. His father's death left him penniless and the sole support of his aging grandmother. He puts his martial arts and parkour skills to use, donning ninja gear to rob an upscale Venetian hotel. But when he's captured on video leaping balconies and climbing roofs, he becomes a viral sensation: the notorious "Ninja of Venice."
On his second outing, the Ninja accidentally witnesses a murder. He sees the killer's face but doesn't know who he is. Videos place the Ninja near the scene, but it's Raffi's long-time nemesis, Carlo, who is charged with the crime. With both the cops and the true culprits hot on the Ninja's trail, Raffi sets out to prove Carlo's innocence without unmasking himself.
The mystery deepens when Raffi uncovers a shocking connection between the murder and his own family, leading him to wonder if the Ninja is merely a thief, or also has the stuff to be a hero.