Although this sounds like an entertaining show, you hardly need a hidden camera experiment to know that Japanese girls fake drunkeness.
One way to judge how much she likes you, in fact, is gauging how she responds to her drinks.
Watch her tolerance when at a large party or ask her friends about it in advance. When you are in a potencially romantic environment together and she seems more drunk than usual, she probablly likes you or one of the other dudes.
Take my word for it. Smart Japanese girls fake drunkeness all the time.