Byakuya Ishigami is an astronaut who resides on the International Space Station. He is not a good swimmer.

Byakuya was the father of Senku. He wasn’t affected by the mass petrification that occurred in Earth along with 5 other astronauts on board. After returning to a petrified Earth, he spear-headed a colony of survivors and founded a village in the hopes that it would aid his son in saving civilisation, the Ishigami Village.