Mr. Sakamoto, a sales team leader at an IT systems company, got off to a rocky start when he was transferred to his current office. At the first meeting with his underlings, all in their 30s, the 43-year-old boss detected a tense atmosphere.

So he decided to break the ice.

"I'm the only one in their 40s, eh? I guess I'm going to raise the average age of the team, ha ha."