12 year old birthday lunch
Where would be a great place to take (4) 12 year olds for a birthday lunch tomorrow?
Chuck E. Cheese's.
Kidding, of course.
I see from your past posts that you always ask about South Bay places, so I'm assuming you want something in the South Bay.
When my little brother was a kid, he and his friends often had birthday parties at the Gable House Bowl, but this was for groups larger than just four. They provide a kids' banquet room (not fancy) for the party, but I suppose you could still just make it an event of your own by simply taking the kids there, going bowling, and buying some food from wherever it is you order food from there.
For a slightly more upscale bowling experience you could always take them to Lucky Strikes at Del Amo.
Of course I'm not suggesting you limit yourself to just bowling places, but that happened to be what first popped up in my head.
You can't go wrong with that age group at the Hard Rock Universal City Walk.
And then you have the walk as entertainment.