Following World War II, a retired professor approaching his autumn years finds his quality of life drastically reduced in war-torn Tokyo. Denying despair, he pursues writing and celebrates his birthday with his adoring students.

When an unconfident young woman is cursed with an old body by a spiteful witch, her only chance of breaking the spell lies with a self-indulgent yet insecure young wizard and his companions in his legged, walking castle.