We originally planned to include Japan but after some initial pilot testing we realized that the country was unsuitable for methodological reasons. Japan has a lot of small “police booths” where people can return lost objects. During our pilot tests, we found that Japanese citizens would not contact the owner but instead drop them off at a nearby police booth. This feature made it virtually impossible for us to assign individual wallets to particular drop-off locations.
Then you have a chicken and egg problem. The cycle will be broken eventually; better to do it now in a controlled manner, even if it will be far from easy.