Dosu Kinuta was a Sound ninja recruited by Orochimaru to test the power of Sasuke Uchiha under the false guide of assassinating him. His introductpry scene was when the group of sound ninja were pointed out by Kabuto as being from a village that had no background or importance in the Chuunin Exams. Hearing the statement and taking it as a direct insult to who he was and what he was doing, and, with Naruto shouting out that he would "never lose to these idiots",
he ran forward, attacking Kabuto and proving that he was not someone to be messing with, and that sound ninja could be quite "vicious", especially when attacked for being new to the ninja world. Of course, it was later stated that Kabuto, being the elite sound nin that he was, did not know that they were actually willing to attack someone, and complimented Orochimaru for picking such willing subordinates for the job. For years Dosu seen Orochimaru
as a father figure and friend, and of the three of the Sound Ninja trio, he was the most powerful. Dosu, like his teammates, was unaware that Orochimaru
had no intention of Sasuke
dying during the Chunin Exams.
He used the power of his Melody Arm to nauseate and confuse his opponents while his teammates attacked. Dosu catches a wiff of the plan and even proceeds to the Chunin Exam finals. However, his desire to fight Sasuke overpowers his better judgment and he attempts a preemptive strike on Gaara only a month before the final exams. Dosu cockily challenges Gaara and is swiftly defeated by the inhuman power of the Shukaku.
Dosu's face was never shown throughout the series when he appeared, and he wore a long fur scarf, the fluffy outline giving him an awkward appearance, along with the bandages around his face. It is never stated whether or not the bandages meant anything to him, and why he wore them, much less why he covered one eye with them.
Kinuta's clan was never shown, and as far as we can discern, his eye color was black. He was covered up quite thoroughly as to make him seem more mysterious, maybe, or Masashi Kishimoto just wanted to try a new design. Dosu spoke softly, but when he did, he spoke with force behind his words. He never backed down from anything, other than Sasuke in his curse marked form, and only because he was worried about Zaku, his teammates safety, and that he had just come to the startling realization about Orochimaru's plan. He used the mechanism on his arm as an amplifier to fight with, using his chakra to manipulate the sound wakes at will. With this technique he was able to make a completely unblockable attack.