Over the course of 23 and 24 August, aircraft from the 25th Air Flotilla carried out preparatory bombing around the airfield at Rabi.
The main Japanese invasion force left Rabaul on 24 August, under Matsuyama's command, at 7:00 am.
The fleet was made up of two light cruisers, Tenryū and Tatsuta, as well as three destroyers, Urakaze, Tanikaze and Hamakaze, in concert with the transports, Nankai Maru and Kinai Maru, and the submarine chasers CH-22 and CH-24.

At 8:30 am on 24 August, Milne Bay GHQ was alerted by an RAAF Hudson bomber near Kitava Island, off the Trobriand Islands, and coastwatchers that a Japanese convoy was approaching the Milne Bay area.
HMAS Arunta – escorting the transport SS Tasman – left the Milne Bay area and sailed for Port Moresby after learning of the invasion force.
Reports of the second Japanese convoy, consisting of seven barges, which had sailed from Buna carrying the force that would land at Taupota were also received at this time.
In response to this sighting, after the initially poor weather had cleared, 12 RAAF Kittyhawks were scrambled at midday.
The barges were spotted beached near Goodenough Island where the 350 troops of the 5th Sasebo SNLF, led by Commander Tsukioka, had gone ashore to rest.
The Australian pilots then proceeded to strafe the barges and, over the course of two hours, destroyed them all and stranded their former occupants.

After the initial sighting, the main invasion force, consisting of the heavy naval screening force and the two transports, remained elusive until the morning of 25 August.
In an effort to intercept it, US B-17s operating from bases at Mareeba and Charters Towers in Queensland, were dispatched, although they were unable to complete their mission as bad weather closed in.
Later in the afternoon, a number of Kittyhawks and a single Hudson bomber strafed the convoy and attempted to bomb the transports with 250 lb (110 kg) bombs near Rabi Island.
Only limited damage was caused to the convoy and no ships were sunk.
After this, due to the withdrawal of the only Allied naval presence in the area – Arunta and Tasman – an RAAF tender was sent to act as a picket in the bay, ready to provide early warning of the approaching Japanese.

Meanwhile, earlier in the day, Clowes decided to shorten his lines and passed the order for D Company, 61st Infantry Battalion, which had been sent to Akioma in the east, to withdraw back behind 'B' Company at KB Mission and reposition itself at the No.
3 Airstrip at Gili Gili.
A shortage of water craft, however, delayed D Company's departure until the evening of 25/26 August after requisitioning three luggers Bronzewing, Elevala and Dadosee.
At around 10:30 pm, the Japanese main force, consisting of over 1,000 men and two Type 95 Ha-Go tanks, had made landfall near Waga Waga, on the northern shore of the bay; due to an error in navigation they came ashore about 3 kilometres (1.9 mi) east of where they had intended, placing them further away from their objective.
Nevertheless, they quickly sent out patrols to secure the area, rounding up local villagers, and established a beachhead.

Later that evening, two of the small water craft that D Company were using to withdraw to Gili Gili encountered the Japanese landing force.
In the firefight that followed, one of the craft – Elevala – was forced to beach and its occupants forced to return to take to the jungle on foot, eventually reaching Gili Gili some time later; the other, Bronzewing, was holed and of its passengers, 11 were killed either in the engagement or by the Japanese following their capture.
Over the course of 23 and 24 August, aircraft from the 25th Air Flotilla carried out preparatory bombing around the airfield at Rabi. The main Japanese invasion force left Rabaul on 24 August, under Matsuyama's command, at 7:00 am. The fleet was made up of two light cruisers, Tenryū and Tatsuta, as well as three destroyers, Urakaze, Tanikaze and Hamakaze, in concert with the transports, Nankai Maru and Kinai Maru, and the submarine chasers CH-22 and CH-24.
At 8:30 am on 24 August, Milne Bay GHQ was alerted by an RAAF Hudson bomber near Kitava Island, off the Trobriand Islands, and coastwatchers that a Japanese convoy was approaching the Milne Bay area. HMAS Arunta – escorting the transport SS Tasman – left the Milne Bay area and sailed for Port Moresby after learning of the invasion force. Reports of the second Japanese convoy, consisting of seven barges, which had sailed from Buna carrying the force that would land at Taupota were also received at this time. In response to this sighting, after the initially poor weather had cleared, 12 RAAF Kittyhawks were scrambled at midday. The barges were spotted beached near Goodenough Island where the 350 troops of the 5th Sasebo SNLF, led by Commander Tsukioka, had gone ashore to rest. The Australian pilots then proceeded to strafe the barges and, over the course of two hours, destroyed them all and stranded their former occupants.
After the initial sighting, the main invasion force, consisting of the heavy naval screening force and the two transports, remained elusive until the morning of 25 August. In an effort to intercept it, US B-17s operating from bases at Mareeba and Charters Towers in Queensland, were dispatched, although they were unable to complete their mission as bad weather closed in. Later in the afternoon, a number of Kittyhawks and a single Hudson bomber strafed the convoy and attempted to bomb the transports with 250 lb (110 kg) bombs near Rabi Island. Only limited damage was caused to the convoy and no ships were sunk. After this, due to the withdrawal of the only Allied naval presence in the area – Arunta and Tasman – an RAAF tender was sent to act as a picket in the bay, ready to provide early warning of the approaching Japanese.
Meanwhile, earlier in the day, Clowes decided to shorten his lines and passed the order for D Company, 61st Infantry Battalion, which had been sent to Akioma in the east, to withdraw back behind 'B' Company at KB Mission and reposition itself at the No. 3 Airstrip at Gili Gili. A shortage of water craft, however, delayed D Company's departure until the evening of 25/26 August after requisitioning three luggers Bronzewing, Elevala and Dadosee. At around 10:30 pm, the Japanese main force, consisting of over 1,000 men and two Type 95 Ha-Go tanks, had made landfall near Waga Waga, on the northern shore of the bay; due to an error in navigation they came ashore about 3 kilometres (1.9 mi) east of where they had intended, placing them further away from their objective. Nevertheless, they quickly sent out patrols to secure the area, rounding up local villagers, and established a beachhead.
Later that evening, two of the small water craft that D Company were using to withdraw to Gili Gili encountered the Japanese landing force. In the firefight that followed, one of the craft – Elevala – was forced to beach and its occupants forced to return to take to the jungle on foot, eventually reaching Gili Gili some time later; the other, Bronzewing, was holed and of its passengers, 11 were killed either in the engagement or by the Japanese following their capture.
Battle of Milne Bay