The title of the song is "Kono Koe Karashite". It's by Aisha feat. CHEHON. Lol. I think this is a pretty nice song. :o. Although, I don't know the Japanese language, I looked up a version with English subtitles and I thought that the meaning of the song was pretty nice. Also, the sound of the song itself sounds very soothing and calm. Lool. There's a bit of rapping in the song and it's quite fitting. :p.
It's really interesting how the past 2 ending songs have been better than the past 2 opening songs. In my opinion, that is. :x. Usually, the opening song is better than the ending song. Lool. But props to the anime producers of Naruto Shippuden for choosing such great ending songs. :o.