Guren Ichinose/Relationships

Aiko Aihara
A sergeant of the Japanese Imperial Demon Army and leader of a fifteen-man squad in the Moon Demon Company during the conflict in Nagoya. She and only a few other soldiers returned after dealing with a noble vampire to where the others were meeting up.

Guren tells her to stay behind and to inform the other squads who would later arrive of where their locations would be and their next instructions. She accepts and in return the others with her are allowed to rest. Shortly afterwards when Guren and the others departed, they are assaulted by vampires including Lacus Welt, René Simm, and Mikaela Hyakuya. After being forcefully interrogated and the suicide of the other soldiers, she is ultimately slayed by Mikaela after revealing to him solely the plans of the Japanese Imperial Demon Army.

Yayoi Endo
A member of Makoto Narumi's squad. She died while fighting against vampires after Mikaela had taken away Yūichirō. She  fought alongside with Guren.

Norito Goshi
A member of Guren's squad since he was 16 back in high school prior to the apocalypse. He enjoys making fun of Guren. A member of the prestigious Goshi family.

Sayuri Hanayori
Sayuri have been a member of Guren's squad since she was 16 back in high school prior to the apocalypse. She cares deeply about Guren's well-being and tends to dote him with extreme loyalty as his retainers. Guren originally thought of her annoying when she attempted to stand out in his eyes during their late teen. On one occasion, she also has a job in 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 confessed to him by the end of volume 2 of Guren's light novels, but he turn 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 reject it. She is a member of the prestigious Ichinose family. Sayuri would usually be worried about Guren's injuries and helplessly cried over it. On the other hand, she always make 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 proves just how much she truly cares about him. Sayuri have also been Guren's retainer since her early childhood days, understanding the mental struggle she have seen him went 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.

Kureto Hīragi
The most likely to become the next leader of the JIDA. He and Guren have a rivalry dating back to high school. He respects Guren's intelligence and ability to produce bearers of Black Demons. He is ruthless and does not hesitate to torture hostages to make Guren or others talk. He suspects Guren is a spy for the vampires or may lead a coup against the Hiragi family, but he also says he trusts Guren and sends Guren on an extremely dangerous mission to Nagoya. A member of the prestigious Hiragi family.

Seishiro Hīragi
A higher-ranking member of the JIDA, he calls Guren a loser and tells him to get lost. A member of the prestigious Hiragi family.

Shinoa Hīragi
She is Guren's subordinate, and he assigns her to be the surveillance officer to both Yu and Kimizuki. Shinoa and Guren have a close relationship, and he says he would even let her kill him. Her sister is the demon inside Guren's sword. After learning that Guren has been experimenting on Yu, she asks him what his real intentions are. She becomes more concerned after learning that her sister may be influencing Guren behind the scenes. However, she remains loyal to Guren. A member of the prestigious Hiragi family.

Shinya Hīragi
Although he was adopted into the prestigious Hiragi family, he is Guren's friend. He joins Guren without orders to help him in the attack on Nagoya.

Tenri Hīragi
Leader of the Japanese Imperial Demon Army as well as the Hiragi family, he looks down on Guren, who is from a lower branch family.

Yūichirō Hyakuya
When Yuchiro escapes Sanguinem, Guren takes him in and trains him as a soldier and secret weapon of the Japanese Imperial Demon Army. Guren knows he was a survivor of the Hyakuya Orphanage and saves him with the intention of experimenting on him. Yu is one of the seraph of the end. They develop a close relationship, and Guren acts as a father/mentor figure to Yu. He can make Yu transform by giving him a certain drug. Yu does not recall any of the experimentation or the transformation.

Rika Inoue
A member of Makoto Narumi's squad. She escaped the slaughter of 2/5 of her squad and along with the others head to Nagoya airport after rescuing the other soldiers at Nagoya City Hall. Devasted by the loss of her comrades, she blames Shinoa due to her actions for allowing Mikaela to take away Yūichirō. Makoto calms her down before deciding for them to head back to the town hall and rescue Guren.

Soon after, Kureto arrives along with a considerable number of soldiers. Releasing the chains that delved for blood to activate the Seraph of the End, Rika ultimately becomes a victim and is pierced through the heart, killing her.

Shusaku Iwasaki
A member of Makoto Narumi's squad. Just like with Rika, he escapes the vampires' ambush and arrived at the Nagoya Airport. Soon after when Kureto arrived, he is brutally stabbed by several chains to help activate the Seraph of the End, dying soon afterwards after telling Makoto to run.

Mito Jujo
Mito have been a member of Guren's squad since she was 15 back in high school prior to the apocalypse. She is a member of the prestigious Jujo family. Mito appears to be a classical tsundere toward Guren during the beginning of the story and before then, confessing her romantic feelings to him in volume 6 of Guren's light novels. Upon confessing to Guren about her love to him, he maturely rejects her. While so, Guren didn't want to hurt her feelings and likes to be just friend as usual. Yet the both of them still consider each other as a very important companion for one another to protect. Mito had always thought of Guren as someone, who she is deeply indebted to when believing that he has actually saved her multiple times. When she is near the brink of being killed by the Hyakuya Sect and being saved by Guren, Mito had thought of him in her mind, a prince charming to the rescue. Even until now, she continues to have an infatuated crush on him, one that remained for over 8 years and left unrequited. Nevertheless, Mito would tries to get involved with Guren whenever she possibly can if he is feeling depressed during his father's fatural because he was the only one, who treats her as a normal girl unlike the strict policy within her family. Though their relationship was first met with hostility every now and then, Mito began to show sympathy towards Guren and his harsh treatment by the higher-ups, regretting the cold things she said to him in the past. Another example was shown when she grew increasingly worried about the struggle Guren is going through like the death of his father, continuing to warm herself up to him.

Taro Kagiyama
A member of Makoto Narumi's squad. He dies while fighting against the vampires after Mikaela had taken away Yūichirō. He fought alongside with Guren.

Shiho Kimizuki
A soldier Guren experimented on. A wielder of a Black Demon. Although he does not want to work with Yu, Yu eventually wins him over. His sister, Mirai Kimizuki, is under hospital care. A member of Shinoa's squad.

Makoto Narumi
A member of his own squad. He suffers the loss of Yayoi and Taro when the vampires ambush them after Mikaela has taken away Yūichirō. Along with most others, he escapes and arrives at the airport. He prevents Rika from killing Shinoa out of anger and resent, but also turning on Shinya and proclaiming that he and a few others will head back to the town hall and rescue Guren.

When Kureto arrives, he's wary of the Lieutenant General and refuses to rest. Later on he openly confronts Kureto about his plans and everything he's suffered. When the chains are released, he witnesses the death of the rest of his squad. Before he could attack Kureto for revenge and be slayed on the spot, he is helped by the Shinoa squad.

Aoi Sangu
She is the personal assistant of Kureto Hiragi. She arrives with him to the airport and releases the chain on his orders, ultimately resulting in the many losses of lives for their blood to activate the Seraph of the End.

Mitsuba Sangu
She is a soldier of the Moon Demon Company. She works under Shinoa as part of her squad. She disagreed with the decision to put her on a squad of rookies, but she later bonds with them. Mitsuba is a member of the prestigious Sangu family.

Yoichi Saotome
He is soldier Guren experimented on and collected after the Hyakuya's downfall. In addition, Yoichi is also wielder of a Black Demon. He becomes Yu's first official friend. He is a member of Shinoa's squad.

Shigure Yukimi
Shigure have been a member of Guren's squad since she was 16 back in high school prior to the apocalypse. She cares deeply about Guren's well-being and tends to dote him with extreme loyalty as his retainers. Although Shigure is a quiet type, she does not speak often when around Guren, but would usually hangs out with Sayuri. She appears willing to follow just about any order Guren gives her. Shigure would also sometimes praise her master's well thought-out plan right after he defeated the nineteenth progenitor, Mel Stefano. She is a member of the prestigious Ichinose family. Shigure is keeping her feelings of love for Guren to herself as unrequited. She wants to be useful for her master and knows that strength alone isn't enough to support him whenever he is in trouble. This also goes along the line of wanting to bear the burden and sharing his master's pain alongside him. Guren is the only one who can broke the cold gaze from Shigure whenever the two are around each other and would also cried about his injuries besides Sayuri. She would go so far as to disobey her master's order if necessary proves just how much she truly cares about him. Shigure is quite observant and keen about what turmoil Guren must be going through as she sees him struggling mentally. On the other hand, she is overly protective of Guren whenever someone tries to make fun of him and look down on him because of his family status. He was the one who rejected the idea of allowing her and Sayuri to participate in the Kiju experiment, but only himself should be the subject for it, caring for the well-being for his retainers.

Ferid Bathory
An extremely powerful vampire, he works with Mika. Ferid plays with Guren on the battlefield at Shinjuku, though it's revealed later that he and Guren had been working together for some time, which explains a lot of the supposed coincidences throughout the story.

Mikaela Hyakuya
A powerful young vampire, who nearly kills Guren during the battle at Shinjuku. Guren calls him a naive brat. He turns out to be Yu's less-than-dead best friend and adopted family member. Guren agrees to help Yu get Mika back. A survivor of the Hyakuya orphanage and a seraph of the end.

Saitō
A vampire disguised as a modified human working for the Hyakuya Sect.

Mel Stefano
A nineteenth progenitor that Guren had difficulty fighting against, resulting in the losses of many lives while in the process of doing so.

Krul Tepes
Guren first met Krul once she arrived at Nagoya. Shortly after, Mahiru overtook his body and commanded Krul's assistance in an experiment at the airport. This told the ruler of Sanguinem that Guren and Mahiru, a woman she knew from eight years past, were connected.

Crowley Eusford
A thirteenth progenitor in Ferid Bathory's faction.

Shahal
A vampire who captured a girl naned Riko who Guren is sent to rescue.

Asuramaru
The demon Yuichiro Hyakuya makes a contract with. He has a connection to Guren.

Mahiru Hiragi (Mahiru-no-yo)
Guren's former fiancée and lover. Inventor of the Cursed Gear, she eventually becomes consumed with her research and becomes a demon. Guren kills her, and she becomes the demon in his sword. Shinoa Hiragi's elder sister. Despite her impressive genius, all she wants is to love Guren. Though while she might let Guren take the lead for the most part, she's not above possessing him to achieve her own ends, which she proves in Nagoya.

Noya
A demon prepared by Mahiru, whom Guren forms a contract with in volume 4 of Guren Ichinose: Catastrophe at Sixteen.