The story of an honest worker: I found a multi-million treasure and gave it to the state

This incident occurred in 2004 in the Japanese city of Kawaguchi.
A worker while sorting household garbage found a bulky package in a container. As it turned out, it contained 28 million yen (at that time more than $ 250,000).
All bills were neatly laid out in envelopes, each of them was 1 million. Only 28 envelopes.
The man immediately reported his find to the police. After the check, the experts confirmed their authenticity.
But who was their master, why they were in the garbage, is still unknown.