Text size In the fast-paced world of auction sales, Takako Nagasawa, Phillips international specialist, is in the thick of it, working with clients from the U.S. and across Asia to buy and sell 20th-century and contemporary art, in addition to design, watches, and prints. Nagasawa’s fluency with the collector dynamics of Japan, Hong Kong, and Korea is crucial to Phillips, as Asian buyers—and increasingly young ones —become a larger part of the collector base. At Phillips spring evening auction in New York this past May, 41% of sales (before fees) were from Asia. It’s a role Nagasawa, age 51, is…