Little Nemo

The young boy Nemo experiences a nightmare in which he is pursued by a locomotive.

Upon awakening the next day, he goes to see a parade welcoming a travelling circus.

However, Nemo is unable to see the circus because his father and his mother are too busy to act as his chaperones.

Later that night, Nemo imitates the act of somnambulism in an attempt to sneak some pie away, which acts against a promise he had made earlier to his mother.

Upon falling asleep that night, Nemo is approached by figures from the parade.

The circus organist introduces himself as Professor Genius and claims that they had been sent on a mission by King Morpheus, the king of a realm named Slumberland.

The mission involves Nemo becoming the playmate of the princess, Camille.

Although Nemo initially has reservations about interacting with royalty of the opposite gender, he decides to set off to fulfil his mission...

Note: This is the first anime to receive a national US theatrical release.