Due to the more or less deflationary economy, Japanese wages have not increased for the better part of three decades. (Deflating prices mean that even with stagnant wages, you're still able to buy more.) Job hopping is unlikely to actually result in increased wages. (Inflation is now coming to Japan due to the general global inflation from the war in Ukraine, so that will be an interesting scenario to watch.)
Japan is a heavily reputation based society. In the way that US uses credit score to determine a lot of things, Japan uses this sort of reputation as a proxy to determine eligibility for many things. As a general example, finding in apartment in Japan requires a guarantor (essentially a cosigner who agrees to act as a fallback option in case you can't pay) and landlords want a Japanese national person or entity to do it most of the time. https://blog.gaijinpot.com/what-is-a-rental-guarantor/
> When I started my own company, I was living in an apartment that I had first rented as an employee of a megacorp. The entirety of the credit investigation was me presenting my business card to them. Possessing it implies both sterling moral character, stable finances, and a responsible party to intercede with should there ever be an issue with me as a tenant. (Japanese landlords and lenders will, as a matter of policy, escalate any disagreement with you to your boss, as the social opprobrium you’ll suffer will get you to quickly cave.)
https://www.kalzumeus.com/2014/11/07/doing-business-in-japan...
Back ~10y ago, the norm was very much that you needed a personal guarantor, and sometimes you could or had to additionally use an assigned guarantor company which may or may not have additional requirements.
These days, the norm is more that you need to provide a local 緊急連絡先 (emergency contact), and sign up with a guarantor company that acts as insurer and usually have a blanket check. One similarity with France is the general requirement of having a verifiable income of minimum 3x of the rent.
Many other points that the author brings up look very different today compared to in 2014.
Reputation is also highly correlated with company stability in Japan.
Such reputation buys you things like A) easier time attracting a future spouse B) respect in certain social circles and transactions, transferrable to your partner and children (yes this is a thing) C) a network of individuals also “smart and hardworking” like you
