I would consider an open box to be "new" personally. As long as the plastic bags inside are sealed that's fine with me. But I do build a lot of Japanese kits.

What I do find interesting is Japanese model shops standards for damaged is insane compared to the West. If I get a damaged box in the UK I expect it to have a big dent in it or like a torn corner. Some noticeable defect. But in Japan you buy a damaged box model and you can't find the damage on it. I recently bought a kit and all I noticed was a damaged corner which I might of caused myself while opening the box and dropping the kit on the floor (big boxes 1 handed each). You're getting a kit as new as if you bought it in a model shop here.