[Sangetsu]

Are you kidding? You could be a 60 year old dressed in a banana suit in Akihabara, and no one would say a word (though some might look twice, trying to figure out who you were cosplaying, or wondering where you got the costume as they might want one too).

I've seen people in Tokyo dressed more strangely than what I just described. Every day here is Halloween (with a few other holidays mixed in), so don't worry about it.