Warren Buffett has plans for 'bigger fish to fry' and needs Japanese stocks to make it happen, says Mark Mobius

• Legendary emerging markets investor Mark Mobius thinks Warren Buffett has plans for something big.
• Buffett raised his stakes in top Japanese trading companies, which could play a role in a later deal.
• "I think he's got a bigger fish to fry. I think he's got plans for something else," Mobius told CNBC.

Warren Buffett's decision to invest more money in five major Japanese companies may be a prelude to something bigger, said billionaire investor Mark Mobius.