I will need to file Tax Return in Japan called 'Kakuteishinkoku' by Mar.15th

I have been a freelance computer programmer since 4 years before,so I need to file Tax return myself.I hear all workers have to file Tax return in America.In Japan,For a company employee,The company deducts employee's salary and company pays the tax.I didn't care about tax at all when I was a company employee,To prepare Tax return is a very cumbersome task.I have to enter 1 year expenses into accounting software.I finally finished entering my commutation and train expenses when Jan.3rd.