山咲 秋也

He is the only son of a famous archaeologist, Mankai Yamasaki.

He inherited his mother's deep knowledge of art, and is interested in painting. He is a member of the art club at school. When Shuuya was seven years old, his mother, Ayaka passed away in an accident during an excavation at an archaeological site. Midori, the family nanny married Mankai becoming his step mother.

He is usually blunt when talking, but he is kind at heart.