Following a sudden accident, twins Haruka and Sora Kasugano have lost both parents. Beginning their lives anew, they return to their childhood home, residing once more in the rural, quaint town just as they did four years ago. Yet, revisiting such a nostalgic place also entails recalling all the memories the two created together, whether those that brought blissful joy or those that caused painful sorrow. Encountering both old acquaintances and new companions, the story of Haruka and Sora becomes increasingly convoluted as their lives are gradually shaped by various acts of love, friendship, envy—and perhaps even lust.