The Japanese government has announced this self-defeating mechanism by which savers' money will be made part of the bank's capital if the private financial corporation is at risk of bankruptcy.
The mechanism will be to convert savings deposits into preferential shares, a scam mechanism already used in Spain to massively rob small savers, or something called "subordinated bonds".
According to some Japanese-language economic media:
By having the investors shoulder part of the loss in a financial crisis, the system will reduce the burden on taxpayers.
Problem here is that savers are not investors. Investors are those who hold capital shares, aka stock, aka equity. What this system does is to force customers into forcibly becoming investors precisely when the investment is collapsing.
Large scale savers will probably have no problem here: they will already be rushing their money to overseas banks, where it will be safer, so the main victims of this scheme will unavoidably be small and middle savers, often people who have been saving all their lives in order to have something to rely on when old.
Japan is by far the most indebted state on Earth. Its stock market woes have been driving the global ones downwards in the last weeks.