|Anime | Novel|
|Relatives||≪Blaze Innovator≫ (Grandfather)|
|Light Novel||Volume 1- Chapter 1 To This Shield----|
|Japanese Voice||Yui Horie|
|English Voice||Felecia Angelle|
Sakuya Tsukumo is the chairman of Kouryou Academy, and the genetic engineer from that institution who takes part in their research. She is also known as ≪Blaze Diabolica≫ because of her grandfather's name, ≪Blaze Innovator≫. She also inherits her grandfather's research about the ≪Lucifer≫.
Sakuya is shown to wear a Gothic style dress, with black hair curled at the bottom part and an appearance that seems to be a 10-year-old girl. She also has dark violet eyes and pale-white skin, and appears to be rather light in weight. She is considered as a very beautiful girl.
Her dress is covered in black clothing style with white frills at some parts She also wears a head dress that almost covers her head, with pink rose at both sides of it.
Based on Tooru Kokonoe's first impression, she poses such "Devilish, or ominous" aura while watching her in the first volume. He also sees Sakuya as heartless, as she forced the weaker students off the island. However, Tooru didn't reconsider when Sakuya bowed and apologized about not informing about the students on the alternate island. But Sakuya didn't deny the fact that she is heartless to throw others away if necessary for her own research, and treating like them as experiments.
She seems to be quite calm, but sadistic at the same time. But as her age she can't hide her dissatisfaction, especially when Lilith Bristol whispered to Tooru (that reached the chairman's ear) that she was truly shy and lied about herself. (That proves to be a little lie of Lilith to make Tooru think that Sakuya was nicer than she appeared.)
Her grandfather was the previous headmaster, we can assume he passed away which lead her to become the current headmaster even at such a young age.
- She mentions that only a handful of people can reach absolute duo.