At this point I think it advisable to explain the position at the time of taking over command and to give a summary of operational experience in the South East Area up till then.
In January 1942 the South Seas Detachment under Maj-Gen HORII (one third of the Zentsuji Division) with naval escort captured Rabaul. Handwritten tablets commemorating the landing were erected in the middle of the town. When I thought of the flourishing prospects of that time, I could not help being affected by the sudden deterioration in the situation.
Early in May, with cooperation between Army and Navy, the capture of Moresby from sea routes was planned. The upshot was the famous Coral Sea battle, in which both sides incurred considerable losses, with the result that the plan for sea capture had unfortunately to be abandoned. In mid May the South Seas Detachment anew entered 17th Army formed by Lt Gen HYAKUTAKE. Since the sea route attack had been defeated, the capture of Moresby was altered to a plan to adopt the principle of joint action by army and navy, first making a landing on Buna beach at the rear of Moresby, then the army, travelling over the peaks of the Owen Stanley ranges, uniting with them from the sea route to capture Moresby.
The G.O.C. 17th Army, Lt Gen HYAKUTAKE, appointed as responsible for the preparatory study of the land route attack one Colonel YOKOYAMA, O.C. 15th Independent Engineer Regiment which achieved fame in the Malaya campaign. Col YOKOYAMA, commanding his subordinate units (besides his subordinate units there were battalions of the Kochi Regiment, etc.), with naval landing parties on 21st July 1942 landed at Basabua and by the end of that month had already advanced as far as the neighbourhood of Kokoda, drove off approximately a battalion of Australian infantry and occupied the place.
During August the South Seas Detachment, led by Maj-Gen HORII, which was fretting from enforced idleness in Rabaul, was given the responsibility of the land attack on Moresby, and began a landing at Buna.
As for the state of things in Australia at the time, after the landing by the Yokoyama units, it was as if the whole country had been shaken.
Australia, being a long way away from South-east Asia, had sent a lot of its troops to the Middle East and there were practically no valuable troops left in the country, so that it is not hard to imagine there was anxiety about the danger the country was in. It was decided to recall the troops from the Middle East and General Blamey, the Commander in Chief decided, as transport ships were slow, to begin air transport to Moresby. However this was not easy.
After the South Seas Detachment landed at Buna, without even a day’s rest it started its operation against its objective, the 13,000 ft high Owen Stanley Range. Leaving the Buna Coast, the South Seas Detachment crossed the Kumusi mountain stream, first routing enemy advanced units, and while crossing the Owen Stanleys wiped out about 6 enemy battalions. By mid-September they had advanced as far as IORIBAIWA, from where they could see the fires of Moresby. Unfortunately, by then the enemy troops in Moresby had been greatly reinforced, so that on one hand their supplies were likely to be cut off, and on the other hand there was the danger of the Allied landings near Buna; so in accordance with an Army order they retreated, weeping tears of blood, and could only occupy a position on the west bank of the Kumusi River. It is hard not to weep for Maj-Gen HORII’s and his men’s disappointment. In this operation there were difficult problems. The place where the Kumusi River could be forded, in their rear supply line, was eventually occupied by Australian far advanced units. The Kumusi River opened up a plain in a valley of the Owen Stanley Range and as it had a torrential flow which emptied into the sea west of Buna, there was no connecting point between Buna and Kokoda except this ford. Thus the life line of the South Seas Detachment could not advance to the coast as they retreated through the very wet belt of sago palms on the left bank of the Kumusi River.
The rivers in New Guinea are different from those in Japan. They are unbelievably rapid and at times it is impossible to cross them. As a result of the disastrous loss of the fording place the South Seas Detachment received vital attacks. Suffering from starvation, with their desire to reach Buna completely blocked, there was no alternative but to cross the sago palm swamp. The sago palm swamp was very unhealthy, and food was non-existent. The starving troops were in a predicament where they would certainly die, and a great number of cases of death and sickness occurred. Fortunately some officers and men who had followed the coast and fallen into an extremity of weakness were able to link up with the base units at Buna but there were very few of them.
The leader of the South Seas Detachment, Maj-Gen HORII, with Staff officer Lt Col TANAKA Toyonaru and several of his subordinates, using a native canoe, descended the river and came out at the coast, but near the mouth of the river the canoe over turned and they were drowned.
But what of the position of the Buna base area troops? The Army units under the general command of Col YOKOYAMA, O.C. 15th Independent Engineer Regt, were responsible for the defence of the Giruwa and Basabua Area, but as these units had a great number of sick, and as there were many people who were incapable of tackling the Owen Stanleys, and others were engineers engaged in road building or were supply troops, its fighting strength was infinitesimal. Furthermore, the naval units, with nucleus the Special Naval Landing Party under Commander YASUDA, were responsible for the security of the airfield and were not suitable for land fighting. In contrast to these weak base units, the Australian Army, as a result of the South Seas Detachment’s retreat, was able to strengthen its troops, and while they were attacking the retreat the Americans landed as ORO Bay, south of Buna and they both attacked with the objective Buna.
The Buna-based army and navy units, joining forces with Giruwa as the centre, occupied and consolidated the defence of positions in a semi-circle. The GOC 17th Army quickly sent reinforcements in the shape of the Kanbutsu Battalion of 38th Division. This unit strengthened the defence of the left flank positions around the airfield guarded by Yasuda Naval Landing Party. The front line positions in the south centre near Giruwa, were guarded by about 1,000 men of the 144th Infantry Regiment commanded by Major TOMITA of the South Seas Detachment, were formed of 41st Infantry Regiment’s Koiwai Battalion, 15th Independent Engineer Regiment, Supply Troops and what units remained of each force; Yamamoto Road Unit C.O. commanded Basabua units occupied the right flank positions, and so a combined defence was organised.
The enemy attacks on Buna gradually became stronger from about mid-November, the bombing of the airfield in particular becoming intense; supplies of ammunition and food were cut off.
The above situation gradually became clear after I arrived at Rabaul H.Q.
2. Buna area situation
3. Fighting near Buna
4. Army planning
5. New Guinea
6. Operation No.18
7. Wau campaign
8. 20th and 41st Divisions
9. Operation No.81
11. Enemy at Buso-Nadzab
12. Nakai Detachment
15. Nakano Group
16. Air and shipping
17. Madang to Wewak