Where is the Metadata saved?

[Nachtigaller]

Hi,
I want to know where the metadata that i manually enter is saved because I would like to, or at least try to, edit it there directly since the gui needs way to many clicks and scrolls. Nfo files are no option either since my media folder is read only and a feature request to make the nfo location customizable didn't got any attention for three years know.
I already checke the 'metadata' folder but there's nothing in it.

Thanks in advance