門 mon (gate)
The mon part always has things added in between the gates

#1) - 門 || mon - kado - || gate - - || info...
#2) - 閉 || shimeru - tojiru - hei || close - - || info...
it looks like someone closing doors by kicking them
#3) - 開 || kai - hiraku - akeru || open - - || info...
it looks like someone keeping doors open with his arms
#4) - 間 || kan - aida - ma || interval - space - room || info...
#5) - 関 || kan - seki - || concern - barrier - || info...
#6) - 問 || mon - tou - || question - ask - || info...

Others:
闇 yami darkness, gloom
閣 kaku tower
閑 kan leisure
閥 batsu lineage, clan
閲 etsu inspection
闘 tou fight