Interest in Japanese language or culture might be the first step toward moving to japan. Many time people ask me, that how to approach Japan for study or job. I was having same question few years ago. I am covering this post in two section i.e study and work. Before elaborating, my personal opinion is that you should have interest in Japanese culture. If you are interested in the Japanese way of quality working, then it will give you the motivation to study Japanese and adapt environment around you.
There are plenty of option while you are approaching Japan as a student.
1- Higher Studies(Graduate, Master or Doctorate)
For higher studies, you can apply for the scholarship from your home country. There are many scholarships(company sponsored i.e Toyota, Panasonic etc, president scholarship and government-sponsored) to come to Japan for higher studies. There is Ministry of Education, Culture, Sports, Science and Technology(MEXT). A common scholarship which I heard from many of my friends. MEXT provide you with the scholarship for max 3+ years and session start from October or march.
2- Japanese Language Course
You can apply MEXT for Japanese language course too and for that, you still need basic knowledge of Japanese language. There are many private institutes in Japan which provide student visa if you are joining language course for 6 months + for pre-college studies. Osaka, Tokyo, Fukuoka, Okinawa, Nagoya and Hokkaido is the place where you can choose based on your interest and cost of living. Cost of living in Tokyo and Osaka is higher than others. Once you have conversational Japanese you can do part time job too (28 hrs in a week)
Job Hunting Section
Get set ready to read each advertisement and followup for the same, and you are about to get the opportunity in job interviews.
Working holiday visa to moving to Japan (limited country can have this facility)
You can engage in work for the purpose of supplementing your travel funds. There are only a few nationalities which are allowed to do work on holidays in Japan.You can check the link for more details ( work holiday links )
Online Job Hunting to moving to Japan
Nowadays many companies allow applicants to have Skype interview. You can apply online through company homepage, job consultant and online job hunting websites.Once you are hired they will sponsor the visa for you.
You, can come to Japan on the tourist visa and give the interview at the same time. You can not convert your travel visa to working visa. If you have the job offer, then your company can apply work permit for you(Certificate of eligibility(COE)). Once you get COE, visit Japan embassy in your country to get entry permit and be ready for your landing in Japan.
Short time Japanese language course (Tourist visa)
If you want to brush up your Japanese while staying in Japan as a tourist, you can join short-term Japanese language course. You can give the interview at the same time. There is weekend startup meet-up too, where you will get the opportunity to sharpen your skills.
Many of the company provide internship for 6 months to 1 year. The internship gives you the opportunity to understand Japanese market. This help you to upgrade your skills as per market need. If you are good at work and there is a vacancy in the company, further they can offer you long term employee position for the same.
You can register for Japanese language class online from your home country and join once you are in Japan. Institute will never change your visa type until unless you enter in the 6+month course.
In both sections which I explained above need at least conversational level Japanese to broaden your way for Job hunting and Higher Studies. Better to research Japanese job market and list up companies which are ok with beginner Japanese level skills and business level english during work.