The worlds yielded by a child’s magical thinking are brought to life in The Imaginary, an anime film from lauded Japanese Studio Ponoc (Mary and the Witch’s Flower). Adapted from the children’s novel by A.F. Harrold, the film follows a young girl named Amanda and her invisible best friend, or Imaginary, Rudger, who go on wild adventures together — flying through the sky on a giant bird or sledding across a snowy expanse among fantastical creatures. No matter where Amanda’s mind takes them, the friends keep their pact to one another: “Never disappear, protect each other, and never cry.”

After a terrible accident involving two strangers separates Rudger from Amanda, the Imaginary begins his own journey of discovery. Rudger takes shelter in a library safe haven where made-up friends live in community. Despite his newfound security, his need to know what’s become of Amanda prompts him to gather the courage to find her, even at his own peril, one last time. “Sometimes imagination is fun, and sometimes it is scary,” says the film’s director Yoshiyuki Momose, who’s worked as an animator on such films as Spirited Away. “An Imaginary is in an equal relationship with the child who imagined it, but then disappears when the child stops imagining and forgets it; it is a very cruel and sad [existence].”

A loving portrait of childhood and the power of the imagination, The Imaginary also confronts the difficult topic of letting go, just as its source material did years before. Remembers Harrold of writing the book: “I suddenly had a strange epiphany that I’d been writing a story that wasn’t just an adventure. My mum had died a few years [earlier], and my dad had died 10 years before, and this book, it turned out, was about that grief, forgetting and remembering, as well as being a gripping adventure story for brilliant young readers.”