To add some more context - the trainsets can have up to 16 cars with a capacity of up to 1300 people. So basically up to 20800 people per hour.
Also 16 trains per hour means 3.75 minutes between trains. This is actually not that remarkable & we saw that in action last years in Hiroshima, with three trains scheduled from the same platform with departures 3 minutes apart.
This is doable due to a couple of factors:
- passengers are usually quite disciplined and know what to do, eq. people queue at the door before a stop for quick departure
- the trains stop exactly in the same place on the station, so the are markers for each card & door on the platform - due to this people can queue on the platform for their car right where the car will be once the train arrives
- the are marked areas near the door location on the platform for disembarking passengers, so they don't mix up with people waiting in the queue to get in - no chaotic "fan" of people around a car entrance with some trying to get in and others trying to get out at the same time as you often see on European train stations
- all Shinkansen are EMUs with all wheels powered, resulting in rather high yet still comfortable acceleration speed - due to this the tran can quickly stop in the station and the n rapidly speed up again
The end result is a train that comes in rather quickly yet manages to stop on the spot with centimeter precision. Then people disemabark, then people get in and the train can leave & pick up speed again. We timed it once & it all took about 90 seconds.