It is the Spring of 1942, as the Imperial Japanese fleets and armies continue their victorious advance across the Pacific, Rabaul Harbor has become the most important base on the road to Australia.
As commander of the IJAAF Sentai (fighter squadron) based at Rabaul, you are responsible for the defense of the ships in the harbor against Allied air attacks. These may come from either raiding aircraft carriers or airfields in New Guinea.
While your observers in New Guinea will give ample warning of raids from that direction, carrier strikes may not be spotted until they are very close to Rabaul and are hard to stop.
While your Ki43s are highly maneuverable and can out-climb any Allied fighter, you must find and exploit any weaknesses in the opposing aircraft to win.