Months after Sony Corp. bought So-net, the broadband provider's chief chided Sony CEO Kazuo Hirai for having his "priorities in the wrong order."

He told Hirai his focus should be on restructuring the struggling electronics conglomerate rather than spending time and effort buying a firm it had previously spun off, said a person familiar with the exchange.

That was two years ago and Hirai was sufficiently impressed to hire Kenichiro Yoshida as Sony's chief strategy officer. Within a matter of months, Yoshida was promoted to chief financial officer.