Tsunenari Tokugawa drew a salary for more than 38 years, climbing the corporate ladder to become executive vice president of major marine shipping company Nippon Yusen K.K.

But something that had been on his mind for the last 10 years of his corporate life prompted him to retire last month. His duty now is to preserve the treasures left by his ancestors, the family that founded the Tokugawa Shogunate.

"It may sound other-worldly," said a smiling Tokugawa, 62, during a recent interview.