Hiroyuki Sanada: Yeah, of course. I haven’t watched all of the episodes, but most of them. But yeah, I was a big fan.
IGN: Being on Lost means being part of a big mythology, full of mysteries. We’re you prepared to be a part of a show with so many secrets?
Sanada: Well, I learned that after I joined them. I knew the show because one of the cast – Matthew Fox who plays Jack – I worked with him before on the move Speed Racer. We didn’t have any scenes together, but we spent a lot of time in Berlin. Dinner and drinks. So I watched Lost because of Matthew. And then after I decided to join them I had a long time until I got a script so I spent a whole month catching up on all 120 episodes. Five episodes a day. I learned everything.
IGN: How was your character, Dogen, explained to you when you took the role?
Sanada: When I met the creators, Damon (Lindelof) and Carlton (Cuse), they explained my character to me. He was kind of a doctor who had lived on The Island for a long time. I asked them why a Japanese man would be living on The Island and how he might have come to The Island. So now I know why and how, but I can’t tell you. (laughs)
more here : IGN interview