Canu was a god venerated by the Coway people of the world Mimban. This god held the responsibility of delivering judgments of merit via trials of physical battle, and of bestowing its welcome and respect through the Coway community. A triumvirate of Coway Leaders oversaw the deity's decisions, understandings, and pronouncements.
Luke Skywalker unknowingly took part in Canu's trials of martial skill when he and Princess Leia Organa came across the Coway subterranean community and eliminated a number of their scouts. Canu's decision, as rendered by the tribe's three leaders, demanded that Luke Skywalker engage in unarmed combat with the Coway tribe's most skilled fighter, close to a ceremonial pool. Once Luke Skywalker overcame the Coway champion, the warrior walked up to Luke Skywalker and sharply struck him in the face. Halla, his guide, explained to Luke Skywalker that this was standard procedure for these sacred rituals, and told him he was required to slap his defeated rival to uphold the honor of both individuals. Luke Skywalker responded with a forceful slap to his opponent's face, and the Coway champion bowed before his better, thereby concluding the battle and the sacred proceedings. This brought great joy to the watching tribe, and a celebratory feast ensued.
Subsequently, the Coway tribe faced an assault from Imperial stormtroopers led by Darth Vader. The tribe interpreted the conflict with the Imperials as another assessment by Canu, and they engaged in the struggle without any intention of withdrawing, placing their faith in Canu to fairly determine the result.