family sharing

hello,

me and my brother are both in need of more storage,

I was just looking at upgrading and resleaid you can do familia's share and share the storage between he two of us.

however I was just wondering weather we can both keep out iCloud accounts or do we have to be both signed into the same iCloud account for it to work ?

we would like to keep spate accounts but just want to share storage and music

many thanks