Suha is a girl just entering her teens, and she's not happy. She's mourning her father who died a year ago, she's having constant arguments with her mum, and she's terrified of the dark. While staying at her grandma's country home, Suha encounters a squat little man in a spacesuit, called Omu. He's the Astro Gardener, a single-minded celestial caretaker, who protects the "dark" of the galaxies from the handsome but dangerous galactic pirate Pluto.
Suha embarks on an often funny space adventure, featuring a super-cute puppy (who later becomes two super-cute puppies), a scary hulking henchman who has a marshmallow heart, and a baseball game to save the universe. But Won Jong-shik's Astro Gardener also explores a troubled adolescent girl's dreams, which are sometimes joyful, sometimes dark, but finally empowering.