随方毘尼 - even if one were to depart to some slight degree from the teachings of Buddhism, it would be better to avoid going against the manners and customs of the country.

本文
仏法の中に 随方毘尼 と申す戒の法門は 是に当れり、此の戒の心は いたう事 かけざる事をば 少少 仏教に たがふとも 其の国の風俗に 違うべからざるよし 

月水御書
［方便寿量読誦事］
（１２０２頁）
文永元年４月
（１２７８年）

通解（意訳）
（日本の古来からの風習に従うべきかという、弟子からの質問に対して）
 仏法の中に「隨方毘尼（ずい ほう び に）」という教えがあり、これが質問の答えにあたる。
 この教えの意味は、仏法の教えから極端に外れてないのであれば、少々仏教とは違うことがあっても、その国の国土や風俗、社会情勢に従うほうがよいという意味である。

 どんな土地や場所であっても、南無妙法蓮華経の唱題を根本にして、その土地柄や風習に則って、誠実な振る舞いを実践していくべきであろう。

English Gosho
 When we scrutinize the sutras and treatises with care, we find that there is a teaching about a precept known as following the customs of the region that corresponds to this.

 The meaning of this precept is that, so long as no seriously offensive act is involved, then even if one were to depart to some slight degree from the teachings of Buddhism, it would be better to avoid going against the manners and customs of the country.
 [ The most important thing does to chanting the Daimoku every kind of land and place in foundation, and conforms to the nature of the locality and custom, and sincere behavior should be practiced. ] 

*This Gosho is the answer for the question of the pupil whether "Should obey the manners and customs from ancient times."

" The Recitation of the “Expedient Means” and
 “Life Span” Chapters "
April, 1278.
"The Writings of Nichiren Daishonin", Vol.1, p. 72
[ --- ] is liberal translation.

参考文献：「日蓮大聖人御書全集」
「御書をひもとく」「英語で学ぶ御書」　第三文明社
Bibliography : "The Writings of Nichiren Daishonin"
"The Record of The Orally Transmitted Teachings"