During the course of the fighting around the Hongorai , the Australians lost 38 men killed and 159 wounded , while the Japanese lost at least 275 men killed . Following the battle , the Australians continued their advance towards Buin at the southern end of the island . Throughout the remainder of the month and into June , the 15th Brigade advanced along the Buin Road , crossing the Hari on 10 June . Beyond the river , the Japanese resolved to hold the food growing areas in order to protect their precarious food supply , and they consequently occupied a series of deep entrenchments . These were steadily reduced with airstrikes and artillery , and the 15th Brigade subsequently crossed Mobiai River before being relieved by Brigadier Noel Simpson 's 29th Brigade in early July .