Where does “グンタマ” come from?

グンタマ (Japanese) comes from Japanese 埼玉, from Old Japanese 埼玉, from Old Japanese 埼 — cape.

Ancestry of “グンタマ”, step by step

グンタマ traces back through two separate lines of ancestry.

via Japanese 埼玉

StepLanguageWordMeaning
1Japanese埼玉{{w|Saitama Prefecture}}
2Old Japanese埼玉—
3Old Japanese埼cape

via Japanese 群馬

StepLanguageWordMeaning
1Japanese群馬a place name, such as that of Gunma Prefecture
Every word from Old Japanese 埼 →Every word from Old Japanese 埼玉 →Every word from Japanese 埼玉 →