Ecchu fundoshi was the main undergarment for Japanese adult males from the Taisho period up to the end of the Pacific War, and it was its prime as the word of fundoshi directly referred to this type of fundoshi, or even the word of male undergarment meant this fundoshi.
大正期から太平洋戦争終了時までの間は日本人成年男子の主な下着は「越中褌」となり、越中褌が「褌」や「男性下着」の代名詞となる程、越中褌の全盛期を迎えた。