They are Asia’s economic giants - yet the historical record of Japan and China continues to cause tensions. China’s leaders accuse Japan of failing to apologise for its wartime aggression – while Japan’s Prime Minister, Shinzo Abe, talks of rewriting the country’s pacifist Constitution. Tensions are rising in the South China seas. Japanese journalist Mariko Oi and Chinese journalist Haining Liu, visit each other's country to explore the intertwineed histories of their two nations and what they mean today.