Just dropping in to say you don't want to plan anything ever for that hallway/lobby area. It's not an actual event space. We only managed to have the shoot in there because a bunch of Yojimbo were really nice and willing to let us crack set up there after our park blocks shoot got rained out. And even then, actually having an event there was really difficult. Because it's a hallway, you have to deal with a variety of fire code regulations, making sure people can move freely in an around whatever you're doing.
Instead, what you guys want to do is submit this as an official panel so you can get a real space for it.
Go
here, scroll down to the bottom where the panel forms are. You only have until June 5 to fill this out, so hurry! If you don't get an actual panel, I'd suggest organizing an outside-of-con-space meetup. Your best bet is the park blocks, since there's generally not as many people there as Pioneer Square. You can run around and be as crazy as you want without making the rest of the con-goers/population of Portland angry about how Hetalia cosplayers behave in public in general. And if you have a real panel, people who aren't on the Kcon forums will find out about your meetup and have a chance to show up and hang out.
/threadstalk