Further, Tomo is deemed as one of the candidate sites that may have been the land of 'Toma' that appeared in the Gishiwajinden (an 'Account of the Wa [inhabitants of the western Japanese archipelago in the late third century]' in "The History of the Wei Dynasty" which comprises "The History of the Three Kingdoms" written by Chen Shou, where the account is known as the first historical record of Japan).
また、鞆は魏志倭人伝に書かれる「投馬国」の推定地のひとつともなっている。