Japan and China will mark the 50th anniversary of the normalization of ties on Thursday, and it has been a diplomatic roller coaster ride over that half century.

Although the two nations enjoyed warm ties in the early stages, their political relations have become more complicated over the past couple of decades with the rise of China’s economic and military power.

But in terms of economic links, the two neighbors — currently the world’s second- and third-largest economies — have seen ties thrive. China is now Japan’s biggest trading partner, with the total value of trade having grown by about 113 times since 1972 to ¥38.4 trillion last year, according to data released by the Finance Ministry.