Suzu, an android constructed to replace a deceased boy named Ryo, embodies his grieving parents’ attempt to preserve their son’s legacy. Produced at the Personality Plant facility, he undergoes recurrent artificial memory implants meant to simulate Ryo’s life and persona—processes that strain his cognitive architecture as foreign memories clash with his synthetic consciousness. During a motor function assessment, Suzu’s errant baseball lands in a neighboring structure, prompting him to retrieve it. There, he discovers Hotori, a girl imprisoned in the facility by a degenerative illness that dissolves her memories. Despite his programmed origins, Suzu exhibits emergent humanity through compassion and unease, particularly as he witnesses Hotori’s solitary battle against oblivion. Their dynamic hinges on inverted vulnerabilities: Suzu buckles under the weight of imposed memories, while Hotori disintegrates beneath their loss. Through their exchanges, questions of selfhood and transience surface, framed by their shared yet opposing plights. Suzu’s emotional maturation unfolds through his deepening bond with Hotori, compelling him to counter her loneliness until a critical pact forms between them. The story confines itself to their confined world, emphasizing their connection and the existential tensions inherent to their unstable realities.