訓 ひら(く),あ(ける) ・ 音 カイ
Sino-Vietnamese: khai
門 (gate) framing two hands 廾 lifting the crossbar out of its brackets. That is the exact gesture of opening a door.
Stroke data: KanjiVG (CC BY-SA 3.0) — kanjivg.tagaini.net
窓を開けてください。 (まどをあけてください)
Please open the window.