IN SOUTH KOREA August 29th is a date of national humiliation. On that day 100 years ago, the nation fell under the cosh of Japanese colonisers whose coercive annexation treaty stated bluntly: “His Majesty the Emperor of Korea makes the complete and permanent cession to His Majesty the Emperor of Japan of all rights of sovereignty over the whole of Korea.” Japan's heavy hand was lifted in 1945 and it has since made occasional gestures of contrition. Yet it took a century for a Japanese leader to admit that colonial rule was imposed against the will of Koreans.

Japan seems to be trying a bit harder to improve relations with its closest neighbour. Its prime minister, Naoto Kan, offered a “heartfelt apology” for Japan's actions, a few weeks ago, as part of a broad summer effort to show it is both genuinely remorseful and keen on a “future-oriented” relationship. For the first time in 45 years, Japan has offered to send some precious imperial loot back to Seoul. And on August 15th none of Mr Kan's cabinet joined an annual pilgrimage to the Yasukuni shrine honouring Japan's war dead–the first time since the 1980s that there has been such a show of sensitivity about Japan's war crimes.

Some reports (mostly in South Korea) even suggest that Mitsubishi Heavy Industries, a big Japanese firm, may discuss compensating 300 Koreans who were forced, as girls, to work unpaid in an aircraft factory in Japan during the war. That may go nowhere, but even mention of individual payouts for forced labour has been taboo since a bilateral reparations treaty in 1965.

These gestures have taken place amid strong diplomatic Japanese backing for South Korea's tough stance towards North Korea over the sinking of the Cheonan, one of its naval frigates, in March. In a rare act of security co-operation in July, Japan also sent military observers on joint American-South Korean naval exercises.

South Korea has reacted cautiously. Its business-minded president, Lee Myung-bak, also wants closer bilateral ties, and saw Mr Kan's apology as helpful. But historical grievances still matter hugely to South Koreans. It was not lost on them that Mr Kan pointedly failed to direct his apology to North Korea, which suggests some political expediency. Nor has Japan conceded any claim to sovereignty over an island claimed by it and South Korea alike. An editorial in the Korea Herald has urged South Koreans to keep their humiliation “etched in stone”. Yet it also called for more co-operation with Japan.

The best prospects may be over trade. Since 2004 free-trade talks between Japan and South Korea have been blocked by domestic concerns in each country over heavily protected rice industries and car markets. Yet bilateral trade has doubled in the past decade, and business lobbies are urging their governments to resume talks.

Cutting a trade deal could eventually help the countries put the tortured past behind them, especially if the governments could include China, which has its own deep historical grievance with Japan. But that would require strong Japanese leaders, able both to defy nationalists and protectionist farmers at home and to offer evidence of repentance abroad. South Korea's government, too, would have to persuade its people that they should focus on the an enterprising future rather than the past's tragic victims.