Seino Unyu, the providers of the famous Kangaroo moving service in Japan, started out as a very small one-
Of course, SIS's main customer is Seino Un'yu, and SIS would suffer horribly without Un'yu's patronage. Likewise, Un'yu would also be in quite a fix if SIS cut off it's information services which are so crucial to Un'yu's complicated transport network. So the two are a team, and will succeed or fail together. And it goes without saying that the two companies hold much of each other's stocks, both as an act of good will and as protection from hostile corporate takeovers.
As often happens with the daughter companies, it might soon be said that SIS has outdeveloped her mother company. In other words, she is no longer satisfied in doing business with just Un'yu, and now offers the VAN (Value Added Network) information services to other companies, such as mail order companies, who store their products in Un'yu's warehouses and subcontract with SIS to handle the orders and sales promotions.
With this kind of business going on it is very easy to see why companies huddle into groups. They subcontract everything they possibly can, and if they can't, they'll create a company department to do it themselves. And when that department grows, it has a high chance of being established as a separate company, for the benefit of all companies in the group. Though this has a definite flavor of pre-World War II zaibatsus, it is a completely accepted and legal system, and the companies rely on it for security.
As I came into work one morning, two people from Toyota Vista stood in the lobby handing out fliers announcing an upcoming car sale. I was surprised that they had been permitted to do this and asked one of my colleagues about it. He seemed quite surprised that I was astonished, and explained that Toyota is in Seino's group and that Seino's employees have a moral obligation to both seek and sell the services of its peer companies. His sincerity in the explanation was a perfect example of group mentality on the personal level.