Masamichi Katayama, the founder of interior design firm Wonderwall, has a lot of friends. But as he glances around the empty meeting room of his studio, he says, "I feel a little lonely."

A month ago, the same room housed numerous objects and artworks, while a huge ox head (an art piece by Simon Fujiwara) presided over meetings and a menagerie of stuffed animals watched from a window on the floor above. These are the "friends" Katayama misses — all of which, in April, were moved to the Tokyo Opera City Gallery for "The Encyclopedia of Masamichi Katayama: Life is hard ... Let's go shopping," a large exhibition of the designer's collection of books, CDs, antiques, artwork and many, many other things.

"I actually don't see myself as a 'collector,'" Katayama says, explaining his accumulation of more than 500 objects. "I'm 'meeting' items and falling in love. It's about encounters."