Layered underwear - Layered underwear

…Undergarments have become outerwear, just as the chemise that was once worn underneath has become the outerwear of shirts and blouses. Even today, as clothing becomes more casual, what was once underwear, such as T-shirts, is being incorporated into fashion as outerwear. [Ikeda Takae]
[Japanese underwear]
In the broad sense, it includes undergarments, aigi (internal garments), and layered undergarments. Intergarments are a general term for anything worn between a top and an undergarment, but in the Edo period they referred to small sleeves worn under uchikake by women of samurai families, and today their remnants remain in bridal attire and are called kakeshita (undergarments).

*Some of the terminology that refers to "Otoshi-shi" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…下着の表着（うわぎ）化はかつて下に着ていたシュミーズが表着のシャツやブラウスとなったように，今日でも服装のカジュアル化に伴って，Tシャツのようにかつて肌着であったものが表着としてファッションにもとり入れられるようになっている。【池田 孝江】
［和装の下着］
　広義には肌着，間着（あいぎ）のほか襲（かさね）下着がある。間着は上衣と肌着の中間に着るものの総称でもあるが，江戸時代に武家の女性が打掛の下に着た小袖を指し，今日では花嫁衣装にそのなごりをとどめ，掛下（かけした）と呼ばれる。…

※「襲下着」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報