Where does “Kagoshima” come from?

Kagoshima (Portuguese) comes from Japanese 鹿児島, from Japanese 島, from Middle Chinese 島.

Ancestry of “Kagoshima”, step by step

Step	Language	Word	Meaning
1	Japanese	鹿児島	—
2	Japanese	島	an island; one's domain, territory, turf
3	Middle Chinese	島	—

Kagoshima — Etymology, Origin & Word History | Etymology Explorer