One day in 20XX, the alien pig prince who used human bodies as his home arrived on Earth, but unexpectedly discovered that the human beings he was going to live with had not yet been born! The pig prince, who had nowhere to settle down, met Saiji and Ruibi, who were of the same kind. The three of them created various funny accidents on humans, causing them to have baldness, bad breath, headaches, emotional crises and other problems.