Over the past several months, small stacks of envelopes, each containing a 10,000 yen bill (about $85) and a handwritten letter, have been turning up in the restrooms at prefectural offices across Japan. On July 11, officials announced the mystery money has been found in 33 different restrooms in government offices located in 15 prefectures -- Hokkaido, Aomori, Miyagi, Akita, Niigata, Saitama, Chiba, Shizuoka, Tokyo, Osaka, Nara, Hyogo, Oita, Nagasaki and Miyazaki.
In every case where the money turns up, the 10,000 yen bills are each enclosed in separate envelopes with the words "payment" and "one envelope per person" written on them. The envelopes also include a handwritten message asking the finder to use the money to help pay for some sort of study or training.
In Tokyo, a stack of ten envelopes was found in the restroom on the first floor of the Tokyo city office on June 14. Elsewhere in the city, stacks of nine envelopes were found in the men's restrooms at both the Kita and Itabashi ward offices, and a stack of ten was found in a restroom at the Shinjuku ward office.
According to officials in Shizuoka prefecture, where 200,000 yen (about $1,700) was discovered in the restrooms at the city and prefectural offices, each of the 20 accompanying letters written on rice paper featured slight differences in handwriting, indicating a single benefactor wrote each letter by hand.
The first known mystery money appeared in Sendai on April 9, where a stack of six envelopes was found in the first-floor men's restroom of the city office.
All told, more than 2.8 million yen (more than $23,000) has been found in restrooms across Japan.