Do we really not have this?...
A character, usually a pet but human characters can also sometimes play this, wanders away from home, or gets lost, kidnapped etc. While the story on one side will deal with how they cope with life outside their comfortable home and their efforts to find their way back, it will just as much focus on how their friends deal with missing them. Usually will end with An Aesop
for both parties, the runaway learning that There's No Place Like Home
, while their friends that you don't know what you've got 'til it's gone. The reunion can be a Crowning Moment of Heartwarming
(title is of course after Tropey the Wonder Dog
, but taking suggestions)