Prime Minister Fumio Kishida may have witnessed the harsh reality of how investors react when his suggestion of higher capital gains tax rates apparently sent Japanese stocks lower shortly after he was elected president of the ruling party last month.

Heading into the House of Representatives election at the end of October, Japan's ruling and opposition parties are making campaign promises that, if realized, could also have ramifications for financial markets.

Some items are more feasible than others because they are already in the works. But there are also ambitious ideas that experts deem difficult to realize.