Rinji

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

Personality
Rinji has laid back attitude and is rarely worked up about anything. At the same time, he is shown to have sharp intellect and is a planning type. Despite his cheerful appearance, he has shown signs of having a secret agenda.

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 Kurenai. 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 Technique. 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 Kurenai 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.

Soon, Rinji finds himself unsettled as he senses the presence of the Three-Tailed Giant Turtle. After his bats warn him of the enemies' arrival, he has his team set up another smokescreen. Unfortunately, Hinata's Byakugan proves to make the smokescreen meaningless.

The battle is then halted by the appearance of a giant tidal wave. This does however allow Rinji and his men to escape. Afterwards, Rinji begins wondering what is going on as he has lost the ability to communicate with his bats.

After meeting up with Kabuto again, it is then revealed that Rinji was a spy for Orochimaru who was ordered to keep an eye on Guren. It was also revealed that he has spent years acting as spy, inserting himself into villages and even as a fellow prisoner in Orochimaru's dungeon. When talking to Gozu, he claimed his actions are to aid his sickly sister from a far off village. It has yet to be revealed if this is indeed true or yet another lie.

Later as he and his team face off against the Leaf Ninja again, Rinji surprisingly leaves his team to handle his own matters. This ultimately allows the Leaf Ninja to easily take down their opponents. Later he sees Shizune and the others trying to seal the Three Tailed Beast. He tries to stop them but is hit by Rock Lee. He then retreats but returns later with Guren to aid him. Together they are able to stop the sealing.

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".