Japan’s largest business lobby has crafted an ambitious proposal to increase the number of so-called “unicorn companies,” or unlisted startups valued at more than $1 billion, 10-fold over five years as it tries to spur innovation and in turn the country’s slow-growing economy. The Japan Business Federation, also known as Keidanren, aims to increase the number of such firms from about 10 to around 100 while at the same time seeking to expand the number of start-ups by a factor of 10 to about 100,000. Speaking at a recent press conference, Tomoko Namba, the business lobby’s vice chair and founde…