Mawaru Penguindrum

Kanba and Shoma are deeply devoted to their younger sister Himari, who is suffering from a terminal illness. During a family visit to an aquarium, a place filled with cherished memories for Himari, she unexpectedly collapses and dies. However, the situation takes an unforeseen turn when Himari inexplicably comes back to life, now wearing a penguin-shaped hat and joined by some magical companions.