Abstract
Nanpo Bunshi’s famous Teppōki (An Account of Firearms) describes the arrival in 1543 of a ship at Tanegashima, an island off of Kyushu, with Portuguese on board who introduced firearms to Japan. Often, this event is identified with the arrival of some Portuguese in Japan mentioned in contemporaneous Portuguese accounts and the Teppōki is interpreted in light of that. However, this paper argues that there is no good reason to assume that they describe the same events. Another matter often discussed is the nature of Nanpo’s sources, as he wrote his account over sixty years after the event. This article argues that because several of his dates include the cyclic days (analogous to giving days of the week), Nanpo must have had a source written in 1543, or an extract of one, as only someone writing in that year could have known the cyclic days.