I'm literally heartbroken in tears that the girl still wouldn't turn back into human even after 50 years ??????? it's because the pair of machines actually belong to four aliens, and one day on their planet would be 50 years on Earth. They would not be able to restore her on Earth immediately, instead they have to take everything back to their planet and recharge the machines. Another heartbreaking moment in the ending is that while the admirer has become a famous singer, after 50 years he met the granddaughter of his first fan (the high school girl who saw him on steet), and the first fan already passed away.