The way this has worked is that the Japanese economy has bifurcated with the graduation-to-retirement employment being available to a ever smaller group of white collar workers called salary-men. To become a salary-man you have to go to college and get hired the year you graduate through campus recruiting. If you miss your “window” then you can’t become a salary-man and will be stuck in contingent work for the rest of your life.
The people quitting in this case are not salary-men (a salary-man quitting would be pretty unthinkable) but their bosses probably are, hence the cultural divide.
Sometimes salary-men do lose their jobs due to bankruptcy of the organization for instance. Typically the solution if that happens is to jump in front of a train.
Yeah the 13th amendment has a carve-out for prisoners
https://www.youtube.com/watch?v=6lIqNjC1RKU