From Manga Art:
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.
Kawamura Mika
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Miyu Kouzuki is an 8th-grade student whose parents leave for the United States to work for NASA and arrange for her to stay with their long-time family friend, Hōsho Saionji, a monk who lives in an old temple on a hill overlooking the town of Heiomachi. However, Hōshō leaves soon after on a year-long pilgrimage to India, leaving Miyu to stay in the same house with his son,…