Introduced by a college friend. Buddy of mine was visiting my home country, we plan to meet up and he randomly and last minute tells me he's inviting an acquaintance to our meet up. I was a bit annoyed at the sudden change in plans but turns out the rando he invited was a pretty cool lady with a lot of shared interests.
We went to a concert together that weekend, a comic convention the next and the fun kept going.
I knew I'd seen something similar!