Andy Warhol's iconic Campbell's Soup cans, a painting by Takashi Murakami and a word sculpture by Jack Pierson are some of the pieces decorating the head office of Start Today Co., operator of Japan's largest online fashion mall, Zozotown.

The items are just a tiny fraction of the growing collection of CEO Yusaku Maezawa, a billionaire e-commerce mogul and former punk band drummer who sits on one of the many vintage 1950s Jean Prouve-designed chairs accompanying a large, Charlotte Perriand table in his glass-partitioned office on the outskirts of Tokyo.

"When I like something, I thoroughly pursue it," the 42-year-old said during a recent interview with The Japan Times. "That hasn't changed since I was in high school."