"Hachiman Daibosatsu Gudokun" (another title of Hachiman Gudokun) reads, "they looked around Chikushi Province in the night and wrote instructions about the place for naval battle, position and the way to escape" and in addition, the records on Liang-pi CHAO in "Genshi" also says, "envoy to Japan Liang-pi CHAO reached Dazai-fu and returned with detailed information about Japanese titles granted to vassals, the number and names of provinces, customs and products."
『八幡大菩薩愚童訓』には「夜々ニ筑紫之地ヲ見廻、船戦之場懸足逃道ニ至マテ、差図ヲ書」とあり、『元史』趙良弼伝にも「使日本趙良弼、至太宰府而還、具以日本君臣爵号、州郡名数、風俗土宜来上」とある。