Ikoku keigobanyaku (military service) (異国警固番役)
After the Bunei War, it was build up in preparation for the invasion of Yuan (dynasty) again.
Ikoku keigobanyaku was a military service of guarding the coastlines, including the Hakatawan Bay, which was thought to be a potential target of the Yuan's invasion, and the service continued for a certain period of time, led by Shugo (formed in four groups, replaced in every March).
Ikoku keigobanyaku should have been served by Gokenin (an immediate vassal of the shogun in the Kamakura and Muromachi periods), who had their territories in Kyushu, but this service was later imposed on non-Gokenin groups of people, such as administrators of Koryo lands (belonged to the imperial courts) and Jishahonshoryo (lands that belonged to temples and shrines), who were not in the master-and-servant relationship with the shogunate at all, whether or not they resided in East part or West part of Japan, anticipating the Koan Warm
Those served in Ikoku keigobanyaku were exempted from Obanyaku duties in Kyoto and Kamakura. But, the military service was a burden to Gokenin lords in any way.
As the service of Ikoku keigobanyaku was extended, some Gokenin from other areas, but had territories in Kyushu, started to settle down in Kyushu, some could not prevent their branch families from becoming independent in their home province or in Kyushu, and some had their retainers split into the home province faction and the Kyushu faction (e.g., the Chiba clan was divided into the Chiba clan and the Kyushu Chiba clan.)