UFO Baby (1998)

Miyu is an 8th grade girl, whose parents have been hired by NASA. They take off to America leaving Miyu with Mr. Saionji. Later, Mr. Saionji decides to go on a 1 year long trip to India leaving Miyu alone with his son, Kanata. More complications rise when an Alien baby and his babysitter pet crashes/lands in their house. To make things worse, alien baby starts calling Miyu and Kanata Mom and Dad, also showing ESP power and floating around.