When Kamogawa Asumi was a baby, her mother was severely injured by a rocket that crashed onto the ground. Five years later, after a long coma, the mother finally dies, leaving Asumi to grapple with the loss of a mother she barely remembers. Amid her emotional turmoil, she encounters “Lion‑san,” a mysterious figure wearing a lion mask who claims to be a ghost. Lion‑san assists Asumi in burying her mother’s ashes, and the experience leads her to a new resolve: “When I grow up, I’m going to be a rocket pilot.”