Many sub-stories will appear across the Leaf Village and if you planned on a 100 % completion including said sub stories, you are looking at a 10 Hour completion. (ShonenGameZ.com)
The overall game play experience and story line and sub stories flow together well. (impulsegamer.com)
I read that Carver has his own sub story which extends from the graphic novels into the game. (blog.us.playstation.com)