Who's someone who's just a mouth with legs? That's your know-it-all older brother, who won't shut up about anything.
You wish you could box your loud-mouth older brother up and send him far away to きょうと. きょうと is super far away from where you currently live, so just ship your older bro off so he can never bother you again.
Currently there are no similar looking kanji which exist in the WaniKani learning system