A mysterious donor left 40 million yen ($526,000) in a toilet in the administrative building of the northern Japanese city of Hachinohe, local media reported on Friday.
Written instructions said the money should be used to help victims of March's earthquake and tsunami.
City officials said the anonymous donor had slipped in and out unnoticed.
This is not the first time that anonymous benefactors in Japan have chosen toilets to leave cash. On September 29, an anonymous donor left 10 million yen ($131,000) to charity by dumping it in a public toilet. The money was found with a letter saying it should be donated to the victims of the earthquake and tsunami.
In 2007, 400 blank envelopes containing 10,000-yen notes were found in the toilets of local council buildings across the country. Most of that money appears to have been handed in to the police. The mysterious donor was never found.
