Inside the Secret, Years-Long Experiment to Find the Next Head of SoftBank

One or two evenings a month, 300 people gather on the 25th floor of SoftBank Corp.’s Tokyo headquarters for a secretive experiment in corporate succession. The sessions are a cross between night school and a job interview, aimed at finding a replacement for founder Masayoshi Son.

The candidates, employees and outsiders who sign contracts vowing not to disclose material from the discussions and lectures, are rated every session, with the bottom 20 percent cut once a year. Top-ranked today is Nobumasa Mizutani, a 36-year-old who left an investment banking job to join SoftBank and what it calls Academia.