Staff at a Japanese convenience store got a shock when they asked an elderly gentleman to stop reading magazines without buying them, media reports say.
The saw was left running outside the shop
The man, 70, left the 7-Eleven store in the Ibaraki prefecture north-east of Tokyo - and returned with a chainsaw, police told AFP news agency.
After threatening to cut staff to pieces he left the chainsaw outside the shop and carried on reading.
"He was still reading when I called the police," the manager told AFP.
Staff were fed up with the man, who they said arrived at the store every day to read magazines for hours.
The manager lost patience after a three-hour stint on Wednesday and asked him to leave.
Police said the man returned waving the saw and shouting: "I'll cut you to pieces!"
Officers found the saw still running outside the front entrance when they arrested him.
A spokesman for 7-Eleven told AFP it was common for customers to spend a long time browsing magazines but that this was an "extreme case".