The Yamanaka clan (山中一族, Yamanaka Ichizoku) is a family of ninja found in Konohagakure. They specialise in mind related techniques, and they own and run a flower shop in the village.
The members of this clan specialise in mind-centred techniques which makes them experts at intelligence gathering and espionage. They have also displayed sensory abilities and their techniques include transferring consciousness, reading minds and communicating telepathically.
The Yamanaka clan has a special relationship with the Akimichi and Nara clan. For generations, members of these three families have formed an "Ino–Shika–Chō Trio", named after the first part of the names of the members. The Yamanaka members are the "Ino" in the trio. To strengthen the unity between the three clans, a member of the Sarutobi clan will give them special earrings to present to each generation head when they are promoted to chūnin after which they will swear their oaths. The earrings also symbolise that they are considered adults by their respective clans.
The name "Yamanaka" means "in the middle of the mountain".
"Ino", "Shika" and "Chō" are the names of three cards needed for a highly prized trick of "Inoshikachō" in the Hanafuda.
In Chōji's flashback, when his father took him to the Yamanaka, Nara, and Akimichi Clan Memorial. Chōza stated that all three of these clans had mastered secret techniques. None of the Yamanaka's techniques are currently known to be secret, and in fact it had been previously stated that the Yamanaka clan's techniques weren't secret techniques.