In the beginning, there was only Winter. Unable to bear the solitude, Winter drew from its own life to create Spring. However, in response to the Earth's cry of distress, Summer and Autumn were also brought into existence, completing the four seasons. To manage the transition from one season to the next, human children known as Agents of the Seasons were tasked with this sacred duty.

The story centers on Hinagiku, a young incarnated goddess who carries the power of Spring, preparing to rise once again. The season she is meant to oversee and transfer has been absent from the land of Yamato for over a decade. Determined to resume her mission, Hinagiku returns to her homeland, accompanied by her loyal guardian. Together, they travel across the country to confront those who once abducted her.

The narrative follows Hinagiku's journey as she battles the forces that oppose the natural order, seeking to restore the missing season and reclaim her purpose. Alongside her faithful protector, she navigates a world where the balance of nature hangs in the balance, facing enemies from her past while striving to fulfill her role as the harbinger of Spring.