One day, a boy named Leo (Galileo) shows up claiming he is from Pisa, Italy! He says that he had just read a book on the "geocentric theory" written by the astronomer Copernicus. After checking the movement of Jupiter's satellite through the telescope at Ninjutsu Academy, Leo thinks that he may be able to find out the truth behind the geocentric theory. However, Rantaro with suspicious look shows up in front of Leo and...!?