Must see attractions, events and nature in So Cal for Japanese students

I agree about the beach; even if it is cold, an up-close look at a SoCal beach is a very cultural experience that I wouldn't want them to miss out on.
Another idea is Hollywood. When I hosted one of my former Chinese students on a trip here, he WOULD NOT STOP TALKING about seeing the Hollywood sign and checking out the sites in LA; that being said, you could always do Santa Monica or Venice nearby instead of Laguna?? My student was also interested in trying local food. We took him to In-N-Out and bought him a T-shirt and he says he still wears it to this day and talks about his experience eating real, local American food. Yum!
But by far, his greatest experience was Disneyland--it is hard to top. :) Have fun!!

I was once an International student...so yes yes yes on Venice beach and canals. So super cool. Got to soak in some of the skate and surf culture. if they have never been here before, then they'll want to hit up all those iconic places they use for establishing shots on TV e.g. Hollywood, Rodeo Drive, Beverly Hills for celebrity spotting. I think Disney would usually be on the list, but since there is one in Japan, it may not be such a big deal for them. Then I would include at least one thing that will broaden their idea of LA. Getty Center?