TOKYO (AFP) - Chinese President Hu Jintao said Thursday that Japan had nothing to fear from his country's rise and engaged in a round of ping-pong diplomacy on a visit aimed at easing decades of tension. Paying only the second visit ever by a Chinese head of state to Tokyo, Hu was unusually conciliatory about the two countries' tortured history, voicing gratitude for Japan's assistance since World War II. "China has taken a defensive military policy and will not engage in any arms race," Hu said in an address at Tokyo's prestigious Waseda University that was broadcast live in Japan. "We will not become a military threat to any country and we will never assert hegemony or be expansionistic," he said. With Japanese Prime Minister Yasuo Fukuda watching, Hu later took off his jacket and glasses and showed his skill in a brief round of ping-pong with Ai Fukuhara, a Japanese table tennis star who is popular in China. "This is a very strategic (game of) ping-pong. I think we have to remain on guard," Fukuda, a long-time advocate of reconciliation with China, said to compliment Hu's skills. "History is our textbook. The reason why we remember history is not because of our animosity, but because we hope to learn from history to build the future," Hu said. "Friendship between China and Japan serves to bring world peace," he said. A day after welcoming Japan's "peaceful" role since World War II, Hu, in rare remarks for a Chinese leader, praised Japan's decades of low-interest loans to Beijing. "China will forever remember that many Japanese people have put their heart and soul into China's development," Hu said to loud applause. On the Waseda University campus, more than 100 protesters, including students and ordinary citizens, waved Tibetan flags and chanted "Free Tibet" Police separated the protesters from a rival group of mostly Chinese students who shouted slogans in support of the Beijing Olympics. "I decided to take part in this, not because of leftist or rightist political ideologies, but as a citizen," said Tadashi Miyamoto, a freelance event producer. "I can't fathom the reasons for hiding people's deaths."