Sisu, a spunky little kitten, is growing up and loves to get into mischief while playing. But when she spills a few things at home, she runs and hides. This escape takes her on a series of adventures, where she meets new animal friends and discovers the wild outdoors.

When the day is done and night is falling, the kitten finds herself alone. She must rely on her brains and her Sisu, a Finnish word for "strength," to find her way back home.