Tokyo's benchmark Nikkei stock index closed down more than two percent Monday on a stronger yen and disappointment over a lack of asset-buying from the Bank of Japan. The Nikkei 225 index dropped 2.33 percent, or 455.10 points, to end at 19,043.40, while the broader Topix index lost 1.69 percent, or 24.13 points, to 1,405.91. nf/ric/gle