Ryūgan

was a ninja from Takumi Village.

Ultimate Weapon arc
He, along with the rest of Four Celestial Symbols Men abducted Gaara's student, Matsuri, to get access to Gaara. They planned to use the One-Tailed Shukaku inside of him in order to resurrect Seimei so they could seek revenge against the Five Great Shinobi Villages, who they felt did not appreciate their village.

Ryūgan ambushed Gaara and Kankurō which ended with Kankurō challenging him. Ryūgan had the advantage and would have killed Kankurō if Chōji and Kiba didn't come out to help with the battle. Ryūgan obliterated Black Ant and was ready to do the same with the other puppet, but Kiba had a plan. This plan was that Kiba would charge Ryūgan and divert him while Kankurō took the time to repair Black Ant in order to trap Ryūgan within it. Kankurō then used the Black Secret Technique Machine One Shot technique. Ryūgan's agonizing scream could be heard as his blood was pouring out of the doll. Ryūgan's Garian sword was later taken by Hōki.

Trivia

 * His name, meaning "Dragon Eyes" comes from Seiryū, the Azure Dragon of the East.