For the Yamatai-Koku kingdom in Kyushu theory, on the other hand, the amount of ironware excavated from the Setouchi region even after the middle of the end of the Yayoi period was very limited when compared to northern Kyushu, and the level of ironware manufacturing technique was very low compared to northern Kyushu.
一方、邪馬台国九州説では、弥生時代後期中葉以降に至っても瀬戸内地域では鉄器の出土量は北部九州と比べて明らかに少なく、また、鉄器製作技術は北部九州と比べて格段に低かった。