Door = 门 [mén]
Doraemon stands beside his famous door, the one that can take you to any place, any time. Magic or not, it is still a 门.
门 (mén) means “door” or “gate.” The traditional form, 門, still looks like a pair of swinging doors; 门 is the simplified version.
To open the door is 开门 (kāi mén); to close it is 关门 (guān mén). 关门 is also what a shop does at closing time.
请关门。 — Qǐng guān mén. — Please close the door.
商店九点关门。 — Shāngdiàn jiǔ diǎn guān mén. — The shop closes at nine.