Translucent glass

You can see out but the people outside can't See inside. This is how some things are like, not everyone can see what's inside just because they let you see what outside. The characters are like translucent glass, they can see out side the world but no can see the inside. Like all glasses, they can break and they are also fragile but they will glue themselves back together even if they are cracks or even if a piece is missing.