Fū Yamanaka

Fū is an ninja of the village of Konohagakure, and is part of The Foundation.

The Summit of the Five Kage arc
Torune was handpicked by Danzo as his escort, along with Torune, to guard them along the way to the Kage Summit. Later, he is seen walking with Danzo and Torune, and the group is attacked by assasins. Danzo tells them not to do anything, as he needs "exercise", and he reveales his Sharingan eye, ready to fight all by himself.

Abilities
Though Fū has not been shown using any jutsu yet, Danzo stated that he and Torune are among the most skilled ninja in Root.