• 井戸いど — water well
• 井桁いげた — well frame (井-shaped structure)
• 天井てんじょう — ceiling
• 市井しせい — townspeople; the public
• 油井ゆせい — oil well

井 originally depicted a water well. Over time, it came to symbolize shared space and community, as well as the nine-square land division system in ancient China. It reflects both practical life and social organization.

昔むかしは 井戸いどの水みずを使つかって 生活せいかつしていました。
In the past, people used well water for daily life.

市井しせいの人々ひとびとの声こえを大切たいせつにする。
We value the voices of ordinary townspeople.