Rinji

is a shinobi, under Orochimaru, who appears in the second Naruto Shippūden filler arc.

Personality
Rinji has sharp intellect and is a planning type. With this he is able to support Guren's mission. He's sincerely loyal to Guren, but he also seems to have a close relationship with Kabuto.

Three-Tails Arrival Arc
Rinji became Guren's subordinate after the selection battle she and Kabuto held in Orochimaru's hideout. During his time in the hideout, he became comrades with his fellow subordinates Nurari, Kigiri and Kihō, often cooperating with them to win battles.

Later, he and his team are ordered by Guren to take down Team 8. During which, he took on the role of leader and presumably used his sonar powers to allow his team to fight in Kigiri's smokescreen. After feeling he analyzed his opponent's skills enough, he was ready to finish them, until he detected Shino's insect coming. Feeling the increased danger, he ordered his men to retreat.

Later, Rinji watches from afar Guren battling Team 8 with awe. Upon seeing Guren's crystal barrier being destroyed, he is impressed by the enemies' power. He and the rest of the team then run to her aid. Later after Kabuto appears to begin the next part of Orochimaru's plan, he and the rest of the team minus Gozu is left by Guren with instructions to stop their enemies.

Bat Controlling
He has the ability to use ultrasonic waves using the Bat Controlling: Ultrasonic Waves so that he can communicate with bats as he can control them, allowing him to survey the surroundings and give battle instructions to his subordinates.

Sound Detection
He also appears to have a sonar-like power of his own that allows him to detect sound from a large radius.

It is also hinted that he may have a curse mark.

Trivia

 * According to one of the anime's opening themes, Rinji is scheduled to fight Sakura later in the arc.
 * Some people say he resembles Jet from "Avatar The Last Airbender".