開ける
あける · akeru · JLPT N5 · verb-ichidan
to open (v.t.)
🚪🔑 開 = gate 門 + hands lifting the bolt: akeru, a care-oo to unlock
The kanji 開 is a gate (門) with two hands removing the crossbar inside, so the gate opens. Transitive: you open something, marked with を. Its partner 開く (aku) is the intransitive one: the door opens by itself.