Japanese characters are squares

I turned my dietpi on a raspberry pi 2 b into a chromium kiosk.
One of the webpages has Japanese characters on it.
But they all show up as squares.
Is there some locale things or fonts I should install?

Welcome to our community.

Indeed, some additional fonts might be needed. Have a look to following. It’s quite old but there is a statement from 2021 on one of the last post. fonts - Why can't my Chromium display Japanese characters? - Super User

I ended up doing this based on the site.

sudo apt install fonts-takao

And it worked perfectly. Just a reboot. Thank you!