The purchase of a top-class hotel in downtown Tokyo this month by a fund operated by U.S. investment firm Morgan Stanley (MWD.N: Quote, Profile, Research) sent shockwaves through Japan's real estate industry. Not only was the 50 billion yen ($477.8 million) sale of the Westin Tokyo more than 50 times the average size of hotel deals in Japan, it is widely believed to be the country's largest-ever hotel transaction. A clear symbol of surging investor interest in a lucrative market, industry players say.