Japanese stocks are mainly traded in Tokyo stock exchange market.
However Individual Japanese company’s stock can be traded in TSE, investors living outside of japan can invest Japanese stock index such as nikkei 225 or topix.
Japanese population is decreasing year by year. It implies that the Japanese market and demand is shrinking, which has negative impact on Japanese economy. As a whole, Japanese economy and stock market get worse year by year. Of course, growth speed depends on each sectors and companies, so we should carefully choose stocks we invest.
Japan has a serious issue of aging population. Ratio between young and old people are changing and japan has more and more old people while the whole population is decreasing.
Japanese stock market is strongly influenced by American market.
The good way to invest Japanese stock is to buy Japanese index such as nikkei 225. You should buy them when it is in a recession period.