Jiruo

Gender: Male
Species: Human
Occupation: Delver, Delving Instructor
Class: Moon Whistle

Jiruo is a Moon Whistle Delver who serves as a teacher for Apprentice Delvers from the Belchero Orphanage in the town of Orth. While he works as an instructor for the children, he is also largely responsible for their upbringing and well-being.

Jiruo is serious and stern and tends to come off as cold at times but takes his job as a teacher and instructor seriously and prioritizes the childrens' safety. At times he is very insightful and gives good advice, and does his best to support Riko after her mother's whistle was brought back to the surface.

Jiruo was the apprentice of the legendary White Whistle Delver Lyza. Though he was only a red whistle at the time, before she made her last dive, Lyza entrusted him with watching over Riko and protecting her identity as a child of a White Whistle Delver.

(Source: Made in Abyss Wiki, edited)