By popular demand, Tokyo's new panda cub Xiang Xiang is working extra hours from Tuesday, the latest example of overtime in a country famous for its hard-working "salarymen."

Ueno zoo's first baby panda since 1988 will be on display for an extra two hours every day until the end of January and working a full seven-hour day from February to cater to the thousands of fans of the cub.

Munching on bamboo shoots and nuzzling her mother, the bright-eyed 7-month-old has been the object of major media attention, with visitors clad in panda paraphernalia flocking to see her since her first public appearance in December.

More than a quarter of a million fans entered a lottery to get a first glimpse but zoo officials initially limited visitors to 400 per day during a three-hour window.

Until the end of January however, panda fans can get a first-come, first-served ticket to see Xiang Xiang.

And from February, the hours are expected to be extended again - to a seven-hour shift - as the zoo seeks to accommodate up to 9,500 fans of the curious cub.

Some visitors at the zoo on Tuesday were not sure whether the baby panda was ready for grown-up working hours.

Dennis Pook, 36, an assistant manager, said the extended hours were "too much, too fast." "I think the increase is very sudden. If they had extended the hours more slowly and let the panda adapt, it would be a lot better," he said.