Keito Kobayashi runs a business consultancy out of a condominium in Tokyo, but when he needs to hold a face-to-face meeting with clients he reaches for his smartphone and books a room elsewhere.

Kobayashi, 34, is a frequent user of an online conference-room and space-matching service offered by Spacee Inc., one of a number of companies cashing in on the trend for shared offices by tapping into a vast pool of facilities lying idle across the nation.

"As our head office is a unit in a condominium, we use a shared office whenever we have business discussions," Kobayashi said. "When a client wants an emergency meeting, we can readily find an office nearby via smartphone," he said, stressing the convenience of the service provided by Spacee, which operates a network of more than 3,000 shared offices in Japan.