The U.S. and Japan both face problems in dealing with elderly guardianship systems.
Japan is similar to the U.S. in the fact it is dealing with an aging population and facing a growing number of dementia cases.
The impact of the implementation by Japan of a guardianship system in 2000 is discussed in the Japan Times article "Financial misconduct by legal professionals acting as guardians hits record high". The idea of the guardianship system was to help deal with the issue and provide support for elderly dementia patients who were no longer capable of making decisions on their own.
While this program was helpful, it also led to many incidents of elder financial abuse. In 2012, Japan sought to address the abuse situation with a new law that allowed people to place their money in trust banks. Guardians are only allowed to withdraw money from the trusts with the approval of a family court.
Abuse by legal professionals is at its highest point, but that might be because of an increased use of professional guardians.
In the U.S. many advocates are also seeking reforms to state guardianship systems in hopes of eliminating the financial abuse of the elderly, which is a growing cause of concern throughout the country. As lawmakers look for ways to prevent abuse, they might look to what other countries, such as Japan, have done to curb the situation.
Reference: Japan Times (April 13, 2016) "Financial misconduct by legal professionals acting as guardians hits record high"