Default name in Pikmin 4

In Pikmin 4 the default character name is ‘Yuzu’

What exactly causes it to default to this as I am vey sure it would not do this on a switch
Where does it get this name from?

In order for us to provide better support, we need to see the log generated by yuzu. This guide will walk you through how you can obtain the log file: Getting Log Files - yuzu

If I’m not wrong, it comes from Emulation > Configure > System > Device name.
Else, it comes from the profile name, System > Profiles.

Aye. Profile name is what takes it.