Nicolas Cage holds on tight to wife Alice Kim at the premiere of his upcoming film National Treasure: Book of Secrets at the Roppongi Hills mega-complex on Thursday in Tokyo, Japan.

This sequel (the original came out in 2004) involves Abraham Lincoln, his assassin John Wilkes Booth and eighteen missing pages from Booth’s diary.

While doing a press junket in Japan, Cage, 43, admitted the hardest scene to film was a “balancing platform” where he found himself on a flat rock perched above an abyss and quickly had to ‘calculate’ the centre of gravity and shift positions.

“The balancing platform sequence … was complicated because it dealt with physics and mathematics,” Cage said. “Math was never really my strong point, so to have to figure out how to act the math … was a bit of a challenge for me.”

National Treasure: Book of Secrets opens in theaters nationwide on Friday, Dec. 21. More Here! »

Nicolas Cage and wife Alice Kim vacation together off the coast of the Italian island of Capri on Ponza Island, Italy over the weekend with son Kal-El, 22 months.

The property magnate/actor was spotted enjoying a relaxing meal with his wife and taking in the sights on the island before boarding a small boat, which transported them back to their hotel.

You can catch the trailer for Cage’s upcoming film National Treasure: Book of Secrets, out December 21. The film co-stars Jon Voight, Diane Kruger, Helen Mirren, Harvey Keitel and Ed Harris. National Treasure revolves around getting to the bottom of the assassination of Abraham Lincoln.

10+ pictures inside of the Cage clan vacationing in Italy… More Here! »