The most sad you say? Personally to me, the one that was VERY sad and had a real meaning behind it was all of Nagato's team :/ They were trying to strive for a dream they truly felt mattered and they wanted to achieve it no matter what. From going to flashbacks of their childhood to them growing up, you felt you had a connection with them. Yahiko dying for the sake of his team as well as his dream was very depressing to me. He worked so hard for something his whole life only to die young without it coming true, and poor Nagato. He was put with the pressure of carrying on his teammates dream because he truly cared for him. He wanted to help him achiever it no matter what, even though he was blinded in ways. Nagato's death was a lot easier to let go since Naruto was there to assure him that he would win. Konan to me made me cry. The flashbacks involved were very meaningful, and showed their life and how far she had come. She loved Yahiko and he died, then she goes out with an AWESOME fight, but ends up dying in the attempt to make the dream she and her teammates want, come true. To me, that takes devotion and heart. What makes it truly sad though, is that they all died without seeing their dream come true.