Will the woman be a springboard for me to immigrate to Japan?

That woman didn't even go back to Japan. How can she be a springboard for you to immigrate to Japan? If the woman has worked in Japan for many years or has immigrated to Japan, then she can be a springboard for you to immigrate to Japan. Whether it is simple or complicated to immigrate to Japan depends on the applicant's personal conditions. With your personal conditions, it is almost impossible to immigrate to Japan.