1939 turned into 1940. The horrific slaughter in southern China continued unabated. The Japanese had scraped up a new class of draftees, and poured them into the beachhead, landing at Kowloon and Hubei. While the Chinese dealt with this new round of invaders, the garrison of Hong Kong was slaughtered to the man, shocking the British government. The Allies (especially the puppet states of Nepal and Bhutan, anxious to build a counterweight to the Indian juggernaut that lay dormant behind them) poured a continuous stream of technical advice into China, assisting vastly with the nation's modernization effort. China thanked the British by wiping out the Japanese and retaking Hong Kong (while destroying nine Japanese divisions to the last man) on April 2, 1940.
In Qingdao, Chiang's great ambition was realized, when the Chinese transport fleet was revealed and sent to sea. While the Japanese poured their remaining troops into retaking the island of Cheju-Do and threatening Korea, the Chinese fleet sailed blissfully past them and landed at the port of Pusan. 350,000 Chinese veterans marched onto the ships- the largest fleet ever assembled- and landed unopposed outside the city of Hiroshima.
The Japanese government was shocked. They had left only a pitiful garrison of 50,000 in all of the Home Islands- they had never expected so overwhelming an assault, after riding roughshod over China for so long. Chiang Kai-Shek made sure they understood perfectly what he was capable of, overrunning the last Japanese position on Honshu on June 2, 1940.
The garrison of Tokyo, two divisions, put up a feeble resistance, and the rest of the island none at all. Allied pundits (and Winston Churchill, in a remarkable telegram declassified after the war) warned Chiang that Japan would rise up and that every hill and tree would hide a partisan. What the Chinese troops found was city after city of stunned quiet. As the Chinese marched past, the Japanese citizens quailed- perhaps expecting the same treatment their soldiers had dealt out at Qingdao, at Kwangtung, at Hong Kong and Seoul. The Generalissimo strove to the utmost to prevent pillage or other outrages. He was, by and large, successful. The Japanese occupation was remarkably quiet. Chiang said later "I'd rather have stayed there than Nanjing. Everyone was terribly polite."
The Emperor of Japan was swiftly evacuated to the southern island of Kyushu, but Chiang had seized Tokyo's arsenals, the government's stockpiles of supplies, raw materials, and billions of dollars in bullion, currency, and other forms of wealth, much of which was appropriated by the government (and individual soldiers) as "reparations". The Kyushu holdouts were less concerned with how long they could fight off the Chinese than they were with how long they could fight off starvation.
The answer would come soon.