訓 おな(じ) ・ 音 ドウ
漢越音: đồng
A cover 冂 with 口 (mouth) underneath: many mouths speaking under one roof must say the same thing. Same, identical, together.
Stroke data: KanjiVG (CC BY-SA 3.0) — kanjivg.tagaini.net
私たちは同じ学校です。 (わたしたちはおなじがっこうです)
We are at the same school.