Set in Izumo during the Yayoi period, this children's fantasy explores the prosperity brought by rice cultivation alongside the conflicts that arise among people. It imaginatively follows a world at a turning point in history.

A fantasy set in Yayoi-period Izumo, where prosperity and conflict intersect.

Guided by a mysterious key, Noboru steps into another world. To free a sealed castle and bring back his missing father, he must face a dangerous struggle.

A single key leads Noboru into an adventure involving a sealed castle and his father.