A keiretsu is a group of affiliated Japanese companies. In the manufacturing sector, the keiretsu group is organized around a single large manufacturer. For example, companies within the Honda keiretsu are mostly manufacturers of components that Honda Motor Company uses to manufacture cars. (The keiretsu would include other entities as well, including finance and trading companies.)
It is customary for the lead company in the keiretsu group to send “loan employees” to work for a number of years at one of the keiretsu firms. Most of these shukkō-shain are at the senior management level. High-level technical staff are occasionally dispatched as well.
The loan employees are usually given the option of returning to the “mother company.” However, in some cases, there may be an agreement for them to remain in the company to which they were dispatched.