Masked intruders broke into the home of a businessman in Kumamoto early Wednesday and robbed him of more than 10 million yen in cash, police said.

The men broke into the residence of Tetsuo Harada, 56, who runs a restaurant, at around 5:15 a.m., pointed a gun at him and took the money from a safe and other places, police said.

Harada, his wife, 44, and their daughter, 17, and son, 10, were sleeping at the time of the break-in on the second-floor of their home, which has a coffee shop on the ground floor. They were bound with adhesive tape but were not injured, police said.

According to an investigation, the intruders, believed to be in their 20s or 30s, told Harada's wife to open the safe and fled with its contents, including cash.