Why did Japan decide it needed to industrialize?

Because Western Europe and the U.S. had unified countries, Japan thought industrialization would help it unify.
Because Great Britain found success with labor unions, Japan wanted to industrialize to keep its workers happy and engaged. Because a unified Germany was a political threat to Japan, the Japanese decided to industrialize to better prepare for war.
Because Japan thought that industrializing countries of Western Europe and the U.S. would gain a lot of power, Japan felt it needed to industrialize also.

Because Japan realized it was falling behind in terms of military strength and economic power compared to Western nations, particularly after experiencing pressure from imperial powers in the late 19th century, Japan decided to industrialize in order to modernize and strengthen its economy and military capabilities. Industrialization was seen as essential for Japan to compete on a global scale and protect its sovereignty.