Sayuri Hanayori served Guren Ichinose due to her family connections, similar to Shigure Yukimi. Attending First Shibuya High School together, Sayuri vowed to defend Guren and tended to him when other students were looking down on his family background. Becoming acquainted with Mito Jūjō and Norito Goshi as well, Sayuri would also work together with Shinya Hīragi. Becoming members of the Moon Demon Company, she would be a part of Guren's squad. Sayuri would also teach students including Yūichirō Hyakuya along with Shinoa Hīragi then Yoichi Saotome and Shihō Kimizuki too. When vampires attacked, Sayuri was prepared to battle against them. Sayuri interacts with various other characters throughout the Seraph of the End series, which affects herself and the story. This article details Sayuri's relationships with other characters.
He is the leader of Sayuri's squad and the Moon Demon Company. She cares deeply about Guren's well-being and tends to dote him with extreme loyalty as his retainer. Asked to stick by him for the next three years of high school, Sayuri announced of course, since they only reason she was born was to serve him. With Guren mentioning that he had porn magazines so she should leave, Sayuri had heard about this stuff from her brother. With her hand locations, Sayuri affirmed if Guren needs that, then it is an important duty. If Guren did have those needs then he should let her know in advance so she had time to mentally prepare. Guren originally thought of her annoying when she attempted to stand out in his eyes during their late teen. In her new uniform Sayuri asked Guren whether it looks good on her, and that he looked so very handsome in his combat uniform. On one occasion, she also had the job of teaching the students with their training practices in the Moon Demon Company. She appears willing to follow just about any order Guren gives her like jokingly attacking Goshi under his command whenever he goofs off.
On the other hand, she has an unrequited crush on Guren and would accidentally confess to him by the end of volume 2 of Guren's light novels, but he turned her down. In a way, this is why Sayuri would prioritize her infatuation with Guren over anybody else such as when Goshi tries to ask her out for a date and she rejects it. She is a servant to the Ichinose family. Sayuri would usually be worried about Guren's injuries and helplessly cried over it. On the other hand, she always makes curry for Guren to eat for dinner while also thinking that it could win over Guren's heart supposedly. She would go so far as to disobey her master's order if necessary, which proves just how much she truly cares about him. Sayuri has also been Guren's retainer since her early childhood days, understanding the mental struggle she has seen him go through. He was the one who rejected the idea of allowing her and Shigure to participate in the Kiju experiment, but only himself should be the subject for it, caring for the well-being for his retainers.
A member of Guren's squad since she was 16 back in high school prior to the apocalypse. They worked together in investigating a love hotel operated by Ookami. Observing that Shigure was smiling, Sayuri also commented that she was blushing around Guren. They were often seen together and acted in unison on matters. She does not speak often, but gets along with Sayuri very well. Sayuri calls her "Yuki."
A member of Guren's squad since she was 15 back in high school prior to the apocalypse. She appears to be tsundere toward Guren, but he is not interested. A member of the prestigious Jūjō family.
A member of Guren's squad since he was sixteen back in high school prior to the apocalypse. With Mito chiding Goshi on his vulgar talk, Sayuri agrees he should please stop his strange words, before announcing that Guren has yet to make a move on her. She sees him as a joker and play-boy, not tolerating his wild antics. He is a member of the prestigious Goshi family.
A friend from her high school days. He is adopted into the prestigious Hīragi family. She fights alongside Shinya at the battle of Nagoya and when attempting to rescue a captive Guren.
A member of the prestigious Hīragi family and the next head.
A member of the prestigious Hīragi family. Sayuri dislikes him because of the humiliation she faced while duelling him when she was sixteen back in High School prior to the apocalypse.
A member of the prestigious Sangu family. She is Kureto's Personal Assistant and the older sister of Mitsuba Sangū.
She was romantically involved with Guren's. She became the demon in his sword, Mahiru-no-Yo.
A squad leader who who join Sayuri in the vampire noble extermination mission in Nagoya.
Sayuri had Shinoa take part in her class in order to monitor the students behaviour, specifically Yu. She is Mahiru's sister while also being a member of the prestigious Hīragi family.
A trouble-maker in Sayuri's class. He is only in her class for a couple of weeks. He leaves when he receives a Black Demon Series weapon and joins Shinoa's squad.
A trouble-maker from Sayuri's class. He leaves when he receives a Black Demon Series weapon and joins Shinoa's squad.
A student from Sayuri's class. She doubts him being strong enough to accept the demon. He leaves when he receives a Black Demon Series weapon and joins Shinoa's squad.
A member of the prestigious Sangū family. She is the younger sister of Aoi Sangū and a member of Shinoa's squad.
Coming within the vicinity of this seventeenth progenitor Sayuri would concentrate on rescuing Guren from her, Crowley and Horn.
She attempts to rescue Guren from this thirteenth progenitor but is ultimately unsuccessful.
A seventeenth progenitor who Sayuri would attempt to save Guren from.
As a part of Guren's squad, Sayuri helps kills him in Nagoya.
She would fight him in Shinjuku where her efforts to help Guren would be hampered by Lacus.
Though they do not come into one another's vicinity, they were both present on the same battlefield at Shinjuku. Later after the battle in Nagoya whilst retreating, Sayuri found Mika in their escape path. With Mika coming towards her she attacked him using her sword to strike Mika though it broke on contact with his weapon and Sayuri could not prevent Mika's advancement.