How to search for a PhD student opening in Japan? I noticed that the Japanese universities almost never advertise for open PhD student positions on the websites such as phdportal.com or academicpositions.com or researchgate.

I tried to check some Japanese websites, but they assume that the visitor knows the Japanese language, which is not my case.

However I really want to see how are the opportunities in this beautiful country. 

Maybe I should search on more websites, than the ones I mentioned at the beginning?
The best option if you can get accepted is through a MEXT scolarship. Usually, the application process is detailed on the website of the Japanese embassy of your country. Of course there are other scholarships but this one is the most advantageous.
If you can self-finance, you may want to try to enroll as a &quot;Kenkyusei&quot; (research student) for 1/2 years. Being a kenkyusei allows you to do some research under the supervision of a professor (ideally the one who would advise you as a Phd), taking Japanese classes and more broadly getting adjusted to your new environment while preparing for the university's Phd entrance exam. The application process for kenkyusei should be detailed on universitys' website.