Koreans have a strong family and clan attachment and see themselves as individually subordinate to these greater bodies. This sublimation of the individual to the group makes them good team players - so long as they have respect for and a good relationship with the team-leader.
Thus, when working with a Korean team it is imperative to gain their respect through appearing honourable and respectful of others. Respect is also gained through educational achievement, age and experience.
If the right environment can be created, Koreans will prove wonderfully loyal team players. If, however, the environment is uncomfortable (and worst of all a place in which people's face is not protected), then groups will flounder and co-operation can be subtly withdrawn.