The most accurate response to why Japan decided it needed to industrialize is:
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.
During the late 19th century, Japan recognized that industrialization was essential for national strength and the ability to compete with Western powers. This desire to avoid being colonized and to secure its sovereignty motivated Japan to rapidly adopt Western industrial techniques and practices.