This is a direct fork of Friends from Umod: https://umod.org/plugins/friends with filtering to avoid adding NPC and ending up with bloated data files.
/friend <add/remove> <player name or id> -- Add or remove a player as a friend /friend list -- List all of your current friends
It has the same name, hooks and API as Friends so is a plug and play replacement.
It tries to block adding NPC, but some sneak in, so when the plugin saves the friends data it removes all the NPC data. This will also clean up any existing data with NPCs in it. So expect the files to shrink in size on the initial run.