Magellan narrates his family's life in their post-apocalyptic world. His mother has given birth to twins and his sister Marie has grown into a teenager. Magellan works hard to become the responsible heir as his parents spend much of their time meditating. He helps raise and educate the twins. Despite hardships like lack of hygiene and scarce food, the family supports each other and the twins have become good students. However, the cause of their world's destruction remains a mystery.