The US has something like this, but the income threshold is lower.[1] US immigrants in most categories have to show that they will not become a "public charge", that is, need US welfare benefits.
[1] https://www.uscis.gov/newsroom/alerts/uscis-issues-guidance-...
That's reasonable too. People who move to a new country should be able to support themselves there and have a good chance to thrive in their new home. If the average income of the population isn't enough for that to be possible, your country has bigger problems than immigrants
Every single person who came through Ellis Island <https://www.newspapers.com/article/the-brooklyn-daily-eagle-...>
* was a legal immigrant
* had passed a medical inspection
* had proof of having enough resources to pay for their upkeep in the US, or a US financial sponsor guaranteeing same
* was turned away if failing any of the above tests, with no possibility of appeal
Shipping liner companies were charged to return ineligible passengers to their origin (the same is true with airlines today), so they had every incentive to verify ahead of time that they could enter the destination country. The "only 2% of immigrants were rejected at Ellis Island" statistic often bandied-about by the pro-open borders side elides the restrictions that caused the rate to be so low in the first place.
I, for one, am very much in favor of reinstating such barriers to entering the US.
The US requirements are so much lower that calling them similar does a disservice.
The proposed requirements in Japan require earnings to exceed Japan's average and also for them to have an equivalent of 30 years of pension payouts saved up.
The US requirements are not as specific, but for comparison one of the numbers is that that families need to have an income requirement 25% higher than federal poverty guidelines, which very low compared to average US incomes.