In order to search for true love, Princess Mana comes to the Earth from the Moon with his two elder brothers, Kai and Kei. One day as Mana continues to search for his prince, a strange brother and sister appears at the school they attend.

Naoyuki is a kindhearted guy who likes to take care of others. Unfortunately, his hopelessly romantic nature often results in rejections, and his bad taste in men leads him to untrustworthy lovers with terrible morals. Meanwhile, Naoyuki’s childhood friend and next door neighbour Yowu continues to harbour a one-sided crush on him and watches sadly from the sidelines...

XXI century: the moon has been destroyed by a huge asteroid. 15 years later, the earth's climate is changed, leading to instability and making life difficult. The ESA (European Space Agency) sends a team of astronauts in a mission impossible: for replace the moon they must transferring Europa, the smallest satellite of Jupiter, into the earth's orbit.