region surrounding the capital
圻 centers on the area immediately around a capital: the surrounding region or boundary zone that defines the capital's immediate territory.
圻 combines 土 (earth, land) with 斤, which likely contributes a phonetic element. The compound suggests land or territory, fitting the meaning of a region around the capital.
The left side 土 is earth or land, and the right side 斤 looks like an axe. Imagine using an axe to mark the boundary of the land surrounding the capital: the cleared earth defines the region.
For キ, imagine a key (キー) that unlocks the gate to the region surrounding the capital: key -> キ, and the land 土 is marked by the axe 斤.