Below from an Immigration Consultancy with an office in Tokyo :
What you need to know to enter Japan from March 1, 2022
Q1
What is the new process different from "pre-entry screening" required last November?
A1
The new process is pre-registration. This means once you entered all necessary data to the government portal, certificate will be issued immediately.
On contrary, the application for pre-screening was screened by authorities in charge and some were rejected, or asked to amend. In addition, screening process took time.
Sounds like a similar process, but legally very much different.
Q2
What does ERFS stand for?
A2
ERFS stands for "Entrants, Returnees Follow-up System" (入国者健康確認システム in Japanese) You can access to the portal, but currently the system is not opened (There is a rumor that Digital Agency created totally new system though).
Q3
Who shall apply for the pre-registration?
A3
The host companies/organizations need to apply for the new entrants.
Q4
What is the government fee for pre-registration
A4
So far there is no information re; the fee.
Q5
When will the portal, ERFS open?
A5
What we know is that this should be opened latest on March 1 and keen to know if this will be open before March 1.
Q6
Does the short term business traveler also need to conduct pre-registration?
A6
As far as we know as of now, the answer is YES.
Q7
Does the Japanese national, re-entrants (non-Japanese who has resident in Japan and entering with reentry permission) need pre-registration?
A7
No. Japanese national and reentrants are not required to conduct pre-registration process.