Naito Kawaguchi, an ordinary elementary school student, has his cup ramen snatched away by a fat penguin lying in his garden .

The penguin is an alien named "Pa-X" and claims to be the bodyguard of Saria, the princess of the planet Sonab, who ran away from an arranged marriage engagement. Then, Saria also appears, asks her insider for her help, and decides to stay at the Kawaguchi family (Part 1).

Saria, who has become a middle school student and has become accustomed to Earth, receives news from Planet Sonab that her father is in critical condition. Saria and her inner circle fly into space on the spaceship Hyfax (Part 2).