I've never heard of anyone defecting from the Japanese army or navy, period. Which isn't to say it never happened, but I am personally unaware of any such event.

Part of the reason for a lack of defections was the brutal discipline system of the Japanese military. Officers beat the NCOs, who beat the enlisted men on down. This cultivated a culture of fear, one that was intensified by the conformist peer pressure of Japanese society (that one could argue persists to this day).

Secondly, there was a fair amount of propaganda, if not outright brainwashing, by the Japanese government. People were told lies about the war non-stop, and that if you were taken prisoner by the Americans they would skin you alive and eat you. It didn't help that American soldiers did in fact take "war trophies" from dead Japanese soldiers, including skulls and bones. This was a horrifying thought for the Japanese. There was also a certain element of racism involved as well. At one point, Australian soldiers refused to take prisoners to the point that the intelligence section was forced to give ice cream as a reward for prisoners.

Lastly, if you were a kamikaze pilot, and you attempted to defect and somehow got away from your squadron, and headed over to, say, an American carrier or airbase, you would likely have been shot down on sight. Especially after the first few attacks, American sailors were paranoid of enemy kamikaze attacks.