Patterned mirror-shaped paving stone dwelling - Ekagamigatashikiishijukyo

...The functional differentiation of buildings was also observed during the Jomon period. From the end of the Early to Middle Jomon periods, super-large pit dwellings with a length of over 10 meters, known as longhouses, appeared, and were used for public purposes such as meetings in the center of settlements. The patterned mirror-shaped paving stone dwellings with overhangs from the end of the Middle to Late Jomon periods and the huge buildings of the late Hokuriku region (with half-split columns arranged in a circular shape with overhangs at the entrances) are thought to have been used for rituals.
[Yayoi period and after]
The four-pillar style that emerged from the end of the late Jomon period to the beginning of the final Jomon period became mainstream in the eastern part of the country after the Yayoi period, but wall pillars disappeared with the start of the Yayoi period, and roofs reverted to being thatched downwards to the ground.

*Some of the terminology used in reference to "patterned mirror-shaped paving stone dwellings" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…縄文時代には建物の機能分化も認められ，前期末から中期にかけて竪穴の長辺が10mを超す超大型住居，いわゆるロングハウスが出現し，集落の中心にあって集会等の公共的な用途に使用された。中期末から後期にかけての張出しをもつ柄鏡形敷石住居や，北陸地方晩期の巨大建築(半割円柱を平面円形に配置し，出入口に張出しを設ける)は祭祀用と考えられる。
［弥生時代以降］
　縄文時代後期末から，晩期初頭にかけて成立した主柱4本の形式は，弥生時代以後の東国の主流となるが，壁柱は弥生時代に入ると消滅し，屋根は再び地上葺き下ろしにもどる。…

※「柄鏡形敷石住居」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