Al & Li are from a different galaxy. They live on a planet called Kirby. People of that planet have special powers of healing and can come and go wherever they want. The life span on that planet is 1000+ years. They can repair bodies, injuries. They have a cure for all disease. It's all happiness there. They don't need any transportation to go anywhere. But they can't enter earth. To enter earth they have to take birth at earth. To take birth on earth they don't have to die in Kirby. Instead, they have to stay in one special chamber. On a time to time, people from Kirby take birth on earth.