When the Agent of Spring, Hinagiku Kayo, is abducted, spring itself vanishes—plunging the world into unending winter. Refusing to give up, her devoted guard, Sakura Himedaka, searches for her for years. When Hinagiku suddenly returns, the two set out to restore the lost season, face the past that tore them apart, and reclaim the warmth they refuse to lose again.
E1
Ten years ago, the balance of the seasons was broken. Now two girls set out to return spring to a frozen land.
E2
The return of spring arouses painful memories and conflicting feelings in the Agent of Winter.
E3
Hinagiku and Sakura go to stay with the Agent of Summer and stumble into a sisterly feud.
E4
Insurgents attack the Agent of Summer's home. The two Guards fight back.