Why is there no China in Korean treasure hunt?

It is difficult for Korean treasure hunters to create a satisfactory story about China. Treasure Hunt in Korea is a large cartoon about human history, which is quoted from Korea. It takes the country as the unit, and every book has a country. Through the experience of two treasure-hunting teenagers exploring and looking for treasures around the world, a colorful picture of world history is displayed. Because of China's profound historical civilization, it is difficult for creators to tell a convincing story in a limited space.