訓 と(う) ・ 音 モン
漢越音: vấn
口 (mouth) tucked inside 門 (gate): standing at someone's door and calling out. 門 also supplies the sound. To ask, a question.
Stroke data: KanjiVG (CC BY-SA 3.0) — kanjivg.tagaini.net
この問題は難しいです。 (このもんだいはむずかしいです)
This problem is difficult.