Jiruo

Jiruo is stern, disciplined and highly observant. His manner toward the orphanage children can seem cold, but their safety is a genuine priority and he takes both their education and their development as cave raiders seriously.

He is perceptive enough to recognize when the children are concealing something and understands Riko well enough to anticipate the direction her obsession with the Abyss may take. Rather than expressing affection openly, he tends to protect people through preparation and practical advice.

His experience under Lyza also leaves him familiar with the extraordinary personalities of elite delvers. He understands that determination strong enough to drive someone into the Abyss cannot always be stopped by ordinary authority.

Jiruo holds the rank of Moon Whistle, marking him as an accomplished delver permitted to travel considerably deeper than apprentice cave raiders.

He has substantial knowledge of the Abyss, cave-raiding procedure and survival, which he passes to the children under his supervision. His experience as Lyza's apprentice gives him training under one of the most accomplished White Whistles.

Jiruo's strongest demonstrated qualities are judgment and observation rather than a named Relic or extraordinary physical ability.

Jiruo supervises Riko and the other apprentices at the Belchero Orphanage. He is present when Lyza's White Whistle and documents return from the Abyss, understanding the significance they hold for her daughter.

Lyza had previously asked Jiruo to watch over Riko and keep her parentage from becoming public knowledge. That responsibility shapes his treatment of her even as he allows her to develop as an ordinary apprentice.

When Riko secretly begins her Last Dive with Reg, Jiruo's earlier advice and training remain part of the foundation that allows her to survive beyond Orth.

Riko is Jiruo's student and someone he has been entrusted to protect. His stern treatment reflects both his role as an instructor and his responsibility toward Lyza's daughter.

Lyza was Jiruo's mentor. Before her Last Dive, she entrusted Riko's welfare and the secrecy surrounding her identity to him.

Reg is concealed at the orphanage after Riko discovers him, placing Jiruo among the adults the children initially try to keep from learning the truth about him.

Nat, Shiggy and Kiyui are among the children Jiruo supervises at the Belchero Orphanage.

Ozen knew Lyza before Jiruo became responsible for Riko and shares knowledge of Riko's unusual infancy.