Kanba and Shoma deeply cherish their ailing sister, Himari, and are determined to keep her by their side. A simple outing to the aquarium, where Himari holds treasured memories, takes a dark turn when she unexpectedly passes away. Yet, the unimaginable occurs as Himari inexplicably resurrects, adorned with a penguin hat and joined by mystical companions, leaving the siblings astounded by this mystical twist of fate.