Warren Buffett Watch: Berkshire's Japanese stock positions top $30 billion
1. Berkshire's Japanese stocks now valued over $30 billion, up 392%. 2. Buffett continues to buy, potentially increasing stakes above 10%. 3. Mitsui's shares owned by Berkshire valued around $7.1 billion. 4. Buffett plans to hold these investments long-term, signaling confidence. 5. Berkshire may have undisclosed additional investments in Japan.