It is believed that the Edo Bakufu changed its policy to seclusionism after obtaining this information from merchants of Britain and the Netherlands who were aiming to oust Spanish and Portuguese power from Asia, even though the Edo Bakufu during the era of the Ieyasu TOKUGAWA shogunate had positive relations with foreign countries (another theory suggests that Iemitsu was simply a xenophobia.)
江戸幕府はスペイン・ポルトガル勢力をアジアから追放しようとするイギリスとオランダの商人によってこの情報を得て、家康の積極外交から鎖国に方針転換したと考えられている（家光が単に外国嫌いであったという説もある）。