There were six countries to the east of China: North Korea, South Korea, Japan, the Philippines, Malaysia, and Indonesia. Even though there were many of them, none of them were especially powerful, and they did not have much strength to resist.
The closest country to Great Qin was Indonesia. It had 250 regions and roughly 50 million people. Next was Malaysia with 200 regions and roughly 40 million people, then the Philippines with 350 regions and roughly 80 million people. Further away was Japan with 300 regions and roughly 100 million people, then South Korea with 200 regions and around 40 million people, and then finally North Korea with 150 regions and roughly 30 million people.
In total, the six countries had 1,450 regions and around 340 million people. There were also four Nation Armaments from four of the countries: