He and Midori were the personal guards of the unnamed daimyō during the Chūnin Exams. They were assigned to make sure Gaara lost to Sasuke Uchiha, making their daimyō win a bet with another daimyō. When they threatened Gaara to lose, they greatly offended the young jinchūriki, who proceeded to brutally crush Shiba to death, and then Midori, who tried to flee in terror, died shortly after. Their gruesome deaths quenched Gaara's blood-lust, which saved Naruto Uzumaki and Shikamaru Nara from the same fate.
Shiba's forehead protector symbol changed to the Suna symbol right before he died.