If people aren't familiar, "Once Upon a Time In..." is a phrase with a long history in Hollywood for film titles starting with "Once Upon a Time In The West" which is an awesome Sergio Leone Spaghetti Western - maybe the best example of the genre. There was also "Once Upon A Time In America" which was s mob movie with Robert De Niro and James Woods. The title is a very smug insider nod to Hollywood history by the self styled film historian Tarentino.
There's also Once Upon A Time In: China Mexico Detroit Venice Vietnam Brooklyn Amristar Queens Russia Bihar eta: Here's a slightly better poster
Oh he's in it for a lot. In real life he trained a lot of movie stars before the Green Hornet series.