A Tale for the Ages.
Ruri reveals that she learned of Senku's name through a tale passed down to her by her mother. The tale speaks of Senku's father, Byakuya, who became an astronaut after Senku made an electric suit to help him pass the swimming exam for JAXA. Five years after passing his exams, Byakuya travels to the International Space Station, alongside cosmonaut Shamil Volkov and American songstress Lillian Weinburg, joining fellow crew members Connie, Dalia, and Yakov. During their stay, Byakuya and the crew witness the phenomenon that turns everyone on Earth into stone, leaving them as the only six humans left.