Sounds very much like that New Yorker who was so infatuated by
this girl he saw on the train, he put up posters or something
searching for her. He ultimately found her when her friends
saw the posters and contacted her. She happened to be an
Aussie girl there for a holiday.
Anyways, they met, and they got together for a short
while. But they have since broken up. 
This also reminds me of that famous Japanese incident where this
guy helped 'save' a female passenger from a drunk on a train and
she in turn gave him a set of Hermes teacups and thus started a
courtship whereby the man would update on his blog and received
encouragement from lots of Japanese who followed his story.
I'm sure you've heard about it - the blog was compiled into a book,
and there's a movie and TV series on it. It's actually old
'news' cause it all happened a few years ago.
Anyways, good luck to that infatuated guy! 
Got 1 japanese movie also same as this story and also the Sv 74
above incident : Tenshi no Tamago (Angel's Egg)
