I actually went through this system several years ago.
Basically, the system favors famous universities' graduates. Since "big" companies (Toyota, Panasonic, NTT, etc) are in competition with each other during the tight recruiting schedule, they tend to focus recruiting effort on few "good" universities. However, even then, obtaining the best talents are not guaranteed.
Therefore, their solutions are an agreement with those universities, where a number of hiring slots are reserved for graduates from those universities. The universities decide who get the recommendation to which companies.
The catch is, once you are selected for this recommendation, you are STRONGLY compelled to accept offer from that specific company, and withdraw application from all other companies. The students submits their preference to the career councelor and it was considered, but there are cases where people ended up at strange companies. I know someone who was an excellent researcher on image processing and wanted to do DSLR camera development in Canon, ended up as automotive engineer at Toyota because he was afraid of missing out once in a lifetime opportunity, due to the lifetime employment system. (To be fair, due their recent focus on autonomous driving, it worked just fine for him)
I actually managed to secure one of those slots and obtain my first job this way. I have since moved to another company since then as I didn't believe in lifetime employment, but in my case, I actually liked the job. So, it was all good for me.
I can't stress how much these things helped when I first moved to Japan long time ago. Nowadays, you can do real-time translation of kanji just by pointing your smartphone at the signs, but back then you had to copy those kanji by hand to your electronic dictionary, and wrong stroke order means the right character just won't show up.
These simple typography helped me guess the correct stroke order to understand where I was and where I am supposed to go.
Basically, the system favors famous universities' graduates. Since "big" companies (Toyota, Panasonic, NTT, etc) are in competition with each other during the tight recruiting schedule, they tend to focus recruiting effort on few "good" universities. However, even then, obtaining the best talents are not guaranteed.
Therefore, their solutions are an agreement with those universities, where a number of hiring slots are reserved for graduates from those universities. The universities decide who get the recommendation to which companies.
The catch is, once you are selected for this recommendation, you are STRONGLY compelled to accept offer from that specific company, and withdraw application from all other companies. The students submits their preference to the career councelor and it was considered, but there are cases where people ended up at strange companies. I know someone who was an excellent researcher on image processing and wanted to do DSLR camera development in Canon, ended up as automotive engineer at Toyota because he was afraid of missing out once in a lifetime opportunity, due to the lifetime employment system. (To be fair, due their recent focus on autonomous driving, it worked just fine for him)
I actually managed to secure one of those slots and obtain my first job this way. I have since moved to another company since then as I didn't believe in lifetime employment, but in my case, I actually liked the job. So, it was all good for me.