Heart is a tyrannosaurus who is found and raised bv a herbivore mother. After learning his true nature as a meat eater, he runs away from home and finds a baby ankylosaurus egg that hatches and thinks Heart is his father. After accidentally naming the baby Yummie - thinking he looked tasty - their love for one another tests the bounds of nature vs. nurture.

In the final months of World War II, 14-year-old Seita and his sister Setsuko are orphaned when their mother is killed during an air raid in Kobe, Japan. After a falling out with their aunt, they move into an abandoned bomb shelter. With no surviving relatives and their emergency rations depleted, Seita and Setsuko struggle to survive.