About 230 counterfeit 10,000 yen bills were used in transactions in shops near shrines and temples in Tokyo and 11 other prefectures from Dec. 31 to Jan. 3.
The National Police Agency said Tuesday that the areas were particularly crowded during this period with people praying for good luck in 2005.
Police suspect that a single group is behind some of the cases because the fake bills used in Osaka, Kyoto and Hyogo prefectures had identical serial numbers. Those found in Iwate and Miyagi prefectures also had the same number.
Japanese customarily visit shrines and temples at the beginning of each year to pray for happiness. Many of the bogus bills were spent in shops selling good-luck amulets, fortunetelling papers, food and beverages at shrines and temples.
All of the fake bills were apparently made using a color copy machine, police said.
On Nov. 1, the government put in circulation new 10,000 yen, 5,000 yen and 1,000 yen notes with designs aimed at combating counterfeiting.
