The kanji 啓 — “to enlighten, to open up knowledge”
啓 means to enlighten, to open up knowledge and is a JLPT N1 kanji. It has 11 strokes and uses the mouth radical (口).
Stroke order · 11 strokes
On'yomi (音読み)
ケイ
Kun'yomi (訓読み)
ひら(く)、さと(す)
Radical
口 · mouth
Strokes
11
How to remember 啓
Opening a door (戸) and teaching with the mouth (口) at the gesture of a stick (攵) — enlightenment. 拝啓 is the opening word of a formal letter; it ends with 敬具!