Children's homes in Japan are receiving anonymous donations of school bags and other gifts left in the name of a popular manga character.
It began on Christmas Day with a donation of school bags. The donor refused to give his name but left a drawing of a man's face hidden behind a tiger mask.
The drawing is a reference to a classic manga comic pro-wrestler character.
After media coverage, the gesture has been copied across the country.
For the children of the orphanage it was a welcome surprise.
The donor refused to give his name, says local official Yasuhiko Taniguchi, but he did leave a drawing and a note.
It read: "I am Tiger Mask - I have come to your city and I want you to distribute the gifts to all the children's homes here."
For Japan's millions of manga readers the reference was immediately obvious.
Tiger Mask is a classic comic from the 1960s about a professional wrestler who donates his winnings to the orphanage where he was raised.
And after news reports of the first gift on Christmas morning there has been a wave of anonymous philanthropy in the character's name.
Many orphanages have received satchels, others fruit, vegetables and bags of rice.
One donor left more than 92,000 yen (£700) in cash, with a note saying there are Tiger Masks across Japan.