The service is called takkyubin. They shrink wrap and seal your suitcase when you drop it off, in front of you. It's delivered to a special counter at Narita. The pick up counter is before security so TSA wouldn't have anything to do with it. If the shrink wrap is amiss you know someone has been in it. But this doesn't happen in Japan. People who live outside Tokyo and who have to take the shinkansen to the airport use this because you can't take much luggage on the trains and you have to lug it up and down stairs yourself. there are no carts at train stations. I used it when coming back to the States after living a year in Japan and had a large footlocker to send on the plane that was too big and heavy for me to carry.
Here's a website of a company that does this:
http://www.kuronekoyamato.co.jp/engl...s/airport.html
http://www.japan-guide.com/e/e2278.html