A boy called Sho (voiced by Tom Holland) goes to stay with his aunt to rest before an important operation.
One day, he glimpses a tiny figure, Arrietty (Saoirse Ronan), the daughter of the Clock family who live beneath the floorboards, unseen by his aunt or her cats.
Ignoring the warnings about humans from her father Pod (Mark Strong) and mother Homily (Olivia Colman), Arrietty forges an unlikely friendship with sympathetic and kind Sho.
Needless to say, Pod and Homily are terrified that other humans will discover their existence and they will be forced to move to a new dwelling.
Released: July 29 (UK & Ireland, selected cinemas) (U, 94 mins)