Summary
From MangaArt:
After Daa! Daa! Daa!, Ruu is now a cheerful youth living in his home, Planet Otto. Then, a confused girl named Miu arrives through a wormhole from Earth. Ruu joins up with her and promises to take her home. Unknown to Ruu, Miu is the daughter of the same people who took good care of him in his stay on Earth.