This is set before Sanako ever heard of Naruto or Sakura or anyone else! Sanako's time in the Grass village wasn't all leisure and fun. It was difficult. There was blood, sweat, and a hella ton of tears.
This is the end. The horrific future Sanako had been warned about has come true. It's inescapable. What can she do? How is she going to survive? Will she keep her promise made to Naruto's mother?
It's all come down to this very ending. The ultimate choices Sanako is faced with, will she survive? Or will she perish alongside Naruto?