TONY JONES, PRESENTER: It's been erupting constantly for nearly 60 years, spewing out smoke and ash and sending shivers through the more than half a million people who live nearby. Japan's Sakurajima volcano recently blasted 100,000 tonnes of ash more than five kilometres into the sky, reminding surrounding communities of its power and volatility. Vulcanologists warn that the magma chamber beneath the mountain is about 90 per cent full, meaning that a large lava eruption cannot be ruled out. The ABC's North Asia correspondent Mark Willacy travelled to Sakurajima in south-west Japan to see how people live with this rumbling giant.

MARK WILLACY, REPORTER: In legend, this belching giant was named for a beautiful goddess, the divine being venerated as the symbol of delicate earthly life. But Sakurajima is anything but delicate. It is the mother of all Japanese volcanos.

Just across the water from the city of Kagoshima, it is both a tourist drawcard and a troublesome neighbour. And for our visit on this perfect summer's day, the mountain is putting on yet another show.

Sakurajima is one of the world's most active volcanos. Some years it belches into life or erupts over 1,000 times and this bad-tempered beast is just eight kilometres from the 600,000 residents of Kagoshima.

And recently Sakurajima showered this city with 100,000 tonnes of ash, turning day into night and sending people scrambling for cover.

Its 500th eruption of the year sent plumes more than five kilometres into the sky and reminded everyone here just how vulnerable they are to the vagaries of this volcano. But mostly, Sakurajima is just a daily inconvenience.

HIROFUMI KIGUCHIYA, CRISIS MANAGEMENT, KAGOSHIMA CITY (voiceover translation): The most annoying thing is the falling ash. We cannot hang laundry outside. The clothes we wear get filthy and the ash gets in our eyes. People have to sweep it from the front of their houses almost every day.

MARK WILLACY: But the people who are most exposed to the volcano are those who live at its base.

You can understand why people may want to live here. It has a stunning coastline and a relaxed pace and this place is also famous for its fruit and vegetables. Saburo Yokomichi's family has been farming on Sakurajima for nearly 300 years and he's grown used to the volcano's terrible temper.

SABURO YOKOMICHI, SAKURAJIMA FARMER (voiceover translation): When I was a Year Three student at school, I experienced a huge eruption. The sky became like night from the ash and I saw lava flowing down the volcano. But I have become used to it. Me and the mountain are like friends.

MARK WILLACY: But Saburo Yokomichi wasn't around when the volcano last really blew its top. The 1914 eruption was the biggest in 20th Century Japan, generating a large lava flow as well as a tsunami and leaving about 60 dead.

SABURO YOKOMICHI (voiceover translation): My father and his family were evacuated to another island. I still think about a large eruption, but we have learned to coexist with the volcano.

MARK WILLACY: Vulcanologist Masato Iguchi has been studying Sakurajima for more than 30 years, and while he's not worried just yet about another big eruption, he does warn that pressure underneath the volcano is rising.

MASATO IGUCHI, VULCANOLOGIST (voiceover translation): The magma level deep within the volcano is back to about 90 per cent of what it was before the 1914 eruption so we do have to worry about a big eruption in the long-term.

MARK WILLACY: And while we were on Sakurajima, the volcano rumbles into life again, spewing out more ash and giving the people who live here some more cleaning to do. Across the small stretch of sea, the people of Kagoshima go about their business. They can only hope the goddess of the volcano can keep her temper for a little while longer.

Mark Willacy, Lateline.