Heh, I didn't think I could even fix that bug but then again, I found out what was causing it very easily :D
As I don't really trust on JohtoMap to editing people's palette yet, I decided to do so with a hex editor instead (the person in the glitchy house has brown clothes, in original game, they are red). But by accident, I happened to change the "Facing" byte of that person too, and if facing is set to some unused byte, the game may not work properly in the room where that person is so I tried if the game worked by changing the "Facing" back to some normal value and after saving the game in that house, no glitch
I've never gotten this kind of effect before after the change of "Facing" byte so I didn't think that would have caused the problem.
Usually, people (with bad "Facing" value) could be walking out of the map in a glitchy way or do something else like that.
Anyways, next I'll be fixing the grammar a little bit and then have a fixed demo up