A Japanese 10-year-old has become the youngest person authorized to prepare "fugu" pufferfish -- a delicacy that can kill if its poisonous parts are not properly removed.

Fifth grader Karin Tabira passed a test this summer that means she is now certified to slice and gut the fish for consumption.

She recently used her new skills to serve a platter of paper-thin slices of fugu sashimi to the governor of southern Kumamoto region where she lives.

"I was happy when the governor said 'oishi'," meaning delicious in Japanese, she told reporters at an event where Takashi Kimura ate the dish.

Tabira was among 60 people -- mostly professional chefs -- who passed the test in Yamaguchi region this summer, out of 93 people who tried.

Clearing the hurdle was part of "a happy summer break", she said.

Fugu is often served raw at high-end restaurants in Japan, where chefs must hold a licence proving they can safely slice around organs that contain a lethal poison.

Occasionally, unlicensed individuals eat fugu caught in the sea and die.

Yamaguchi does not have an age limit to take the fugu test, but in Kumamoto Kimura can only prepare fugu dishes when accompanied by a licensed adult.

Tabira's interest was piqued by news that a sixth grader in another region passed the test, and she trained since February at Fukunari, a Kumamoto-based farm and wholesaler.

She used a hammer to drive her butcher's knife through the fugu's tough bones, and "had to stand on a platform to use the kitchen counter", Fukunari executive Yuki Hirao told AFP.

"Even our adult staff can fail the test. For a 10-year-old to clear the test first time, it's amazing," she said.