It is presumed that at that time Shimotsuke Province had a strong relationship with Yamato Dynasty; the letters of 'Sasakibe somebody,' who seemed an inhabitant there, was engraved on a piece of a tile excavated from the remain of Kamikounushi Mobara Kanga iseki; Suzumenomiya-jinja Shrine (present day, in Utsunomiya City) was established near that site and Mimorowake no Mikoto, who was considered Emperor Sujin, was enshrined there.
上神主・茂原官衙遺跡から出土した瓦片に刻まれた人名のひとつに近隣住民と思しき「雀部某」の文字が見られることや、この後間もなく、この遺跡の近隣に崇神天皇とされる御諸別命を祭祀する雀宮神社（現・宇都宮市）が建立されるなど、当時の下野国が大和朝廷と近しい関係にあったことを推定させるひとつの事象となっている。