The story revolves around the three siblings of the Takakura family, including the brothers Takakura Kanye (voiced by Subaru Kimura), Takakura Akima (voiced by Ryohei Kimura), and their terminally ill sister Takakura Harumi (voiced by Miho Arakawa). The Takakura brothers, who have a sister control complex, cherish Harumi very much, but the doctor tells them to be prepared to lose their sister at any time. One day, the three siblings went to the aquarium together, but in a blink of an eye, the two brothers found that their sister was missing, and then they found Harumi lying unconscious in the middle of the crowd. Harumi, who was declared dead after failed rescue, actually woke up in the morgue! The two brothers were extremely surprised and took their sister home. Soon after, they received a strange package. After opening it, they found three mysterious penguins inside. These three penguins are naive, and no one can see them except them. What is going on, and how will the gears of fate turn?