"Mavis" and "Emily" H6K and H8K
Just because Japan had flying boats doesn't mean they were also used in the SAR role because they weren't. Japan did not make the effort to rescue their downed airmen like the Allies did, if they made any effort at all. The many Japanese pilots died that would have otherwise lived to fight another day if they were rescued. Not sure of the reason, maybe it's their code of Bushido but the Japanese did not make the effort.
ack-ack