In China's myths and legends, after death, people go through the gate of hell, the ecliptic, between the ecliptic and hades, and the Nai River as the boundary. The helpless river is blood yellow, and there are ghosts everywhere that can't be reborn. Insects and snakes are everywhere, and the wind is blowing. There is a Naihe Bridge on the Forgotten River. There is an old woman sitting next to Naihe Bridge. Her name is Meng Po. If you want to cross the forgotten river, you must cross the Naihe Bridge. You must drink Meng Po Tang to forget your past life. If you don't drink Meng Po Tang, you can't cross Naihe Bridge, and you can't be reincarnated.