The secret world of Arrietty is about this girl who is about 10 centimeters tall who lives under Sho's great aunt's house. Sho arrives at her grand aunt's house because he is sick and needs to get away from the city to be more relaxed but gets stuck into a small adventure around the house with Arrietty. Arrietty and her family can't be seen by humans because they could be taken away or killed. Arrietty gets spotted by Sho and her and her family have trouble by moving out and having to find a new home as the maid of the house captures one of the little people to show off the world that little people truly exist in so Sho and Arrietty team-up.