Mr Han and his six-member delegation sat in silence as their host, the chairman of the railway, rushed off to investigate. The connection with the overhead electrical wires had failed. Not only could the Nozomi - which means 'Desire' - not move, but on a chilly December day the train's heating had stopped.
Two and a half hours later, another train was shunted up the line to pull the Nozomi, the Chinese delegation and the other 900 passengers, to the next station. By this stage helicopters with television crews were hovering overhead and reporters were waiting at the platform to record what had become a national humiliation.
The curse of the bullet train named Desire had struck again. After three decades of almost faultless service by the bullet trains, which have never had a fatal accident, the 170mph Nozomi version, introduced last year, has caused Japan Railways endless headaches, with breakdowns, mechanical failures and other problems.
Japan has the most efficient railways in the world. The Nozomi is the exception that proves the rule. And when something does go wrong, it goes wrong in a big way.
The Nozomi was designed to cut the travel time on the 260-mile Tokyo-Osaka route to 2 hours and 50 minutes - 20 minutes faster than ordinary bullet trains. On a good day, the Nozomi does this - for a return fare of pounds 165. But on a bad day it doesn't make it. Thursday's stoppage caused 24 bullet trains to be cancelled and 21 to be delayed, affecting 45,000 passengers. The schedules leave little room for error: at peak times a train leaves Tokyo for Osaka every 7 minutes.
Trains are part of Japanese daily life. The Transport Ministry says 22.7 billion train journeys are made every year, or 62 million per day - by a population of just 123 million. Some 300,000 people are employed by the railways - one in 20 of the working population. Japan's railways were established 120 years ago; as the country modernised after the 1868 Meiji Restoration, British engineers helped to build the first line, from Tokyo to the port of Yokohama, 15 miles away, in 1872. Less than four decades later, railways linked most of Japan, and by 1907, 140 million passengers and 24 million tons of freight were transported by rail. Trains played a central part in the nation's development: the bullet trains were designed with a view to impressing the world when Japan hosted the 1964 Olympics.
Today the bullet trains have become highly politicised: many politicians have staked their careers on building a bullet train route to their constituency, with all the prestige and economic windfalls that entails.
In 1906 the first de luxe express train, the 'Saikyuko', began travelling between Tokyo and Osaka, with first, second and third classes and a dining car. Today's Nozomi travels the same route, but dining cars have been abolished to increase seating capacity. Train attendants - with white gloves - push trolleys with box lunches, canned drinks and coffee instead. They are scrupulously polite, and bow to the honourable passengers as they enter and leave a carriage. Glamour has been sacrificed to efficiency. The old Saikyuko took 13 leisurely hours to make the journey the Nozomi does in 2 hours 50 minutes - when it arrives.