But their relations have become volatile since the shift in the balance of power in East Asia.

Japan had long considered itself the only power in the region, however, as the Chinese economy has gained strength since 1992, when enormous foreign direct investment from all over the world starting to flow into China, the Japanese economy has stagnated because of its bubble economy burst in the early 1990s.

Against this background, the "China threat" theory emerged in Japan's political and business circles. Some people believed that Japanese aid, trade, investment and technological transfer would lead to the expansion of China's economic, political and military influence in the region and beyond in ways contrary to Japanese interests.

Lack of mutual trust and understanding persist. China's relations with Japan have become increasingly complex over the past two decades, and there are many issues that the two countries have not resolved. Bilateral ties have repeatedly been strained over political issues for many years.

A normal, if not friendly, relationship is easily influenced by domestic political and social factors in both countries.

Among others, the two countries have not fundamentally achieved a real postwar reconciliation even more than four decades after they normalized their diplomatic relations. Differences over issues related to wartime history that surfaced in the 1980s continue to haunt the relations.

During Kishida's stay in Beijing, China and Japan agreed to minimize confrontation and step up efforts to improve political relations.

Yet the two countries face a severe challenge of building mutual trust between their people and between their leaders.

The author is China Daily Tokyo bureau chief. caihong@chinadaily.com.cn