A sushi chef in Japan is still working, even though he just celebrated his 100th birthday. His name is Jiro Ono. He is one of 4,380 people in Tokyo who have become or will be 100 this year. Mr Ono spoke to Tokyo's governor. She asked him about his secret to a healthy life. He replied, "To work." He said: "Even at 100 years old, I'll try to work…The best medicine is to work." He added: "I plan to keep going for about five more years."

Jiro Ono was born in 1925. He started working when he was seven. He qualified as a sushi chef in 1951 and opened his own restaurant in 1965. It was a small 10-seat sushi bar in a rich area of Tokyo. He spent many years trying to make the perfect sushi. In 2011, a movie was made about Ono called "Jiro Dreams of Sushi". In the film, he said: "I haven't reached perfection yet. I'll continue to climb and try to reach the top."