入る
はいる · hairu · JLPT N5 · verb-godan
to enter
🚪 hairu sounds like hi + roo: say hi as you enter the room
入 is the kanji for enter; る is the verb ending. The reading はいる breaks into hi + ru, so tie it to saying hi when you enter a room. It also means to contain or hold: what has entered a box is what the box holds.
入 — single pictograph, two slanting strokes
入 is a pictograph showing an arrowhead or pointed entrance, with two strokes converging downward to suggest something going inward. The original sense was 'to enter,' and it still carries that meaning today. It contrasts visually with 人 (person), where the strokes cross differently at the top.