As a baby, Kamogawa Asumi's mother suffered a serious injury caused by a rocket crash. Asumi's mother remained in a coma for five years until her eventual passing. Asumi struggles with the death of a mother she scarcely recollects. During her struggle, she encounters a peculiar character called "Lion-san", who wears a lion mask and proclaims to be a ghost. Lion-san assists Asumi in burying her mother's ashes, leading Asumi to a strong realization. She ultimately decides that she wants to become a rocket pilot when she grows up.