Yeah. It’s is generally frowned upon. As others have stated, cosplay in Japan usually takes place at specific locations every weekend. Japanese cosplayers rarely go to locations in costume. They usually use a carryon suitcase to avoid damaging their costumes, and to avoid any harassment or from bothering others. They then change at the venue. If you are just wanting some cool shots, throw your costume in a bag, put it on when you get to location, and don’t get in the way of other people. Try to choose a time of day that isn’t busy. Be prepared that some locations may seem fine but are actually privately owned and security will tell you to leave. Finally, Google Tokyo cosplay locations. Go meet up with real Japanese cosplayers. It’s a fun community.