As forms of foundation of an Ie, there are 3 cases which are a branch family, restoration of an abolished family and creation of a family, and as forms of abolition of an Ie there are two cases which are abolished families (廃家) and ended families (絶家).
新たに家が設立される形態として分家、廃絶家再興、一家創立が、家が消滅する形態として廃家、絶家がある。