The low ratio of inward investment basically reflects that overseas firms consider investment in Japan as having low profitability. The other side of the coin is that Japanese firms are doing business in the market with such low profitability.
At any rate, if firms in every country exert their strength and deepen the international division of labor across national borders, this will lead to the advancement of the global economy as a whole. It is important to enhance not only outflow to overseas but also inflow to Japan, as well as create a competitive environment that attracts overseas firms and personnel to Japan.