You Are Umasou adapts Tatsuya Miyanishi's popular picture book about a Tyrannosaurus who comes across an Ankylosaurus baby all by himself and says, "Gaō! Omae Umasou Dana" ("Rawr! You look delicious.") Despite initially wanting to eat the baby Ankylosaurus, the Tyrannosaurus ends up adopting "Umasou" as his own.