Guren Ichinose

Guren Ichinose 「一瀬グレン, Ichinose Guren」 is a Lieutenant Colonel of the Japanese Imperial Demon Army, as well as the captain of the Moon Demon Squad.

Appearance
Guren has medium length black hair and purple eyes. As Lieutenant Colonel, he wears the standard Japanese Imperial Demon Army uniform, with black trousers and boots.

Personality
Guren was naive in his childhood days and spent most of his time with Mahiru. His aspects on life felt simple as he was in his happy moments. But after he was treated with disgust due to his name as a lowly born branch member, he began to feel guilt. He though that because of his weak physique and power, he couldn't reach out for what he wanted, which was hinted to be Mahiru. She motivated him to become stronger and wiser.

He is a wise leader who values teamwork and cooperation, determined to preserve the survival of the human race from demons and vampires. When Yūichirō wants to join the Moon Demon Squad, Guren refuses to allow him until Yu made friends.

He pretends to be lazy, but he actually works hard and keeps many secrets, which he has no difficulty lying about. He plans to dethrone the Hyakuya.

He cares about his subordinates and friends, considering them to be family.

History
Guren was born to the Ichinose family, a low branch family of the Hīragi. He was also the best friend and lover of Mahiru Hīragi, but this was frowned upon because of his low birth. Since they were friends, Guren was treated badly and blamed for, also getting beaten by the adults.

He appears at the end of the first chapter of the manga, using information from a prophecy to collect Yu, a survivor of the Hyakuya orphanage.

Story
Guren arrives outside the entrance of Sanguinem during daytime at the end of chapter 1. He says that one of the lab rats from the Hyakuya laboratories, the company responsible for destroying Japan, is there just like the prophecy said. He tells Yu that Yu will be useful in exterminating vampires. Exactly what prophecy is refers to has yet to be mentioned again the manga.

Over the next four years, Guren trains Yūichirō to become a soldier of the Japanese Imperial Army. He teaches Yu how to survive above ground, how to live in the Demon Army's cities, and how to use a sword. Unfortunately, he is less successful at teaching Yu obedience and subordination, which is shown in 2020 in Shibuya, Tokyo at the beginning of chapter 2. Once Yu is sentenced to high school for his disobedience, Guren assigns Sergeant Shinoa Hiragi to act as Yu's surveillance officer. When Yu refuses to follow orders to make friends, Shinoa gives him a note with the written orders. This note is the first time anyone in the series addresses Yu as a "virgin." Although Shinoa mocks him for being a virgin most often, Guren may have given her the idea to do so in the first place.

During those four years, he also worked on human experimentation for the development of Black Demon Series bearers.

Shinoa finds Guren during chapter 2, alerting him that a vampire escaped onto the school grounds. Guren kills the vampire attacking Yu, giving her an unpleasant surprise when she realizes he used a cursed blade.

Although Guren then rejects Yu's request to join the Moon Demon Company to exterminate vampires, Yoichi appears, tackling Yu and appearing as his friend. Guren makes good on his promise, finally accepting Yu to the Moon Demon Company along with Yoichi.

Shinoa informs Guren when Yu manages to overcome a myo-o demon's thrall on his own. After that, Yu and Yoichi attend their first class class in the Moon Demon Company barracks. After he introduces them, Yu picks a fight with Guren, and Guren assigns Yu the seat in front of Kimizuki. Naturally, the two boys start another fight, and Guren finishes it. Kimizuki asks Guren if he can receive a demon weapon since he is stronger than Yu, but Guren turns him down, warning him that he will be devoured by the demon if he has no bonds to pull him free from the demon's clutches. At the end of chapter 4, Shinoa recommends both Yu and Kimizuki to Guren as candidates for the Black Demon Series weaponry. He plans to rebel against the main family.

In the following chapter, we see him rebelling by sleeping and snoring during a meeting with the higher-ups. He manages to escape a "stupid" political meeting by appearing rude. Yu attacks him, and he decides to proceed with Yu's training so that the upper brass do not notice him. He kicks Yu in the head before continuing with his day.

In chapter 6, Guren appears in the classroom. Second Lieutenant Sayuri Hanayori informs him that Yoichi may be stable enough to resist demonic temptation. Guren attacks the classroom, filling with a demonic aura that sends most of the class tumbling to the floor, many of whom go unconscious. Sayuri struggles to stand by using two spell tags. Yu and Kimizuki tremble. Shinoa manages to remain standing just fine, and Yoichi is completely unaffected by the attack to the point where he does not even feel it. They are the only ones standing. Since he experimented on the three boys previously for this purpose, he is not surprised when they stay standing. Contrary to his expectations, Shinoa remains standing as well, proving herself as a possible candidate for Black Demon Series Cursed Gear as well.

Before he takes the three boys to make contracts with demons, Sayuri informs Guren that Yoichi may not be strong enough to accept the demon, although his heart is very stable. Guren takes him anyway.

Yoichi becomes possessed, and Guren orders Yu and Kimizuki to kill him. In the end, they manage to help Yoichi regain control and turn back to normal from being a man-eating demon, and it is actually Guren's words that make him snap out of it. Shinoa wonders if Guren planned this ending from the start.

When Guren assigns Mitsuba Sangu as the fifth member of Shinoa's squad, she protests against being assigned to a squad of rookies, especially working under Shinoa. Eventually, she submits.

Guren and his team enter the field early on in the battle at Shinjuku. He scouts for the enemy commander, spying Mika and Ferid. Ferid spies him back, which Guren finds mildly concerning. Then, he charges in at the 5th Street intersection, killing several vampires with a single strike. He leads the battle, facing off against Mika.

Guren fights head-to-head against Mikaela Hyakuya, complementing him on his strength. Mika disses him in return. Although he manages to trick Mika and nearly deals him a dangerous blow, Seventh Progenitor Ferid Bathory defends Mika, backhanding Guren and sending him flying. Mika lets Guren chat briefly with his squad but does not allow Guren to take a second dose of the supplement, which has a high risk of sending him into shock and potentially killing him but may increase his power. He notes that Mika is faster than before, and Mika disarms him, stabbing him through the chest and nearly killing him before Yu intervenes.

When he attempts to kill MIka with Yu's help, Yu freezes, and Mika escapes. Although Yu desperately wants to reclaim Mika, Guren issues orders to retreat. Ferid plays with Guren, eventually grabbing him by the neck. Ferid swindles his opportunity to kill Guren, and he asks him about Yu, even though Ferid already knows the answers. Guren calls Yu's transformation his "ace in the hole" after subduing the it by commanding Shinoa to embrace Yu. Guren makes a comment about being a decoy, and Ferid notices Major General Shinya Hiragi, barely escaping a sniping attack. The main forces arrive, chasing away the vampires. He rejects Shinoa's request for answers, and she spends five days hunting him down before finding him in a lab underground.

Yu went berserk because Guren had Shinoa give him a special supplement. Although she asks Guren about it, he gives her no straightforward answers, and he only tells her that the medicine should wear off in five days and Yu should wake up soon.

Natural Abilities
Guren is an intelligent scientist, capable of developing Cursed Gear. He even creates a method with a very high rate of success for the development of humans, who can bear Black Demon Series weaponry. He proves himself as a capable swordsman, strategist, and leader on the battlefield. He is rumored to have even recaptured Shinjuku from the vampires with a single team.

Magic and Spells

 * Fudo Myo-o Spell: Guren is capable of using enchantments on spell tags.  In particular, this is an ancient one that causes an explosion after a few seconds.  Guren uses this as a distraction in his battles against Yu and Mika.

Demon Weapon

 * Mahiru-no-YoGlen's_Demon_Possession.png possession-type demon weapon of the Black Demon series bound into the form of a sword. The demon inside was originally a human named Mahiru Hiragi, his former lover, whose research eventually turned her into a demon until Guren himself killed her.

Trivia

 * Guren is the main character of the novels, titled Seraph of the End: Guren Ichinose's Catastrophe at 16.
 * The writer, Takaya Kagami, thinks of Guren as "The Unparalleled Ichinose!" while writing him.
 * Guren means "Crimson Lotus."
 * Ichinose means "One Rapid."

Quotes

 * "There he is. Just like the prophecy said.  One of the lab rats from Hyakuya Laboratories, the company that destroyed Japan.  Boy.  You are going to be of use to me in exterminating vampires."--Guren to 12-year-old Yu after escaping Sanguinem, Chapter 1, "The World of Blood Legacy"
 * "Sorry, Kid. The army doesn't have use for virgins who are too scared to work in a team, make friends, or date.  If you want in, then make a friend at that school and introduce them to me.  I'm not holding my breath.  YOU FAIL!"--A note from Guren to Yu, Chapter 2, "Humanity After the Fall"
 * "Quit screeching. Nobody wants to hear it, Vampire."--Guren to the escaped vampire, Chapter 2, "Humanity After the Fall"
 * "Nope. I hate brats who don't know what 'teamwork' means."--Guren rejecting Yu from joining the Moon Demon Company, Chapter 2, "Humanity After the Fall"
 * "Okay, listen up. The reason that I, your homeroom teacher, decided to grace you all with my presence today is because we have two transfer students...  Anyway, here they are.  Yuichiro Hyakuya and Yoichi Saotome.  They're the idiot and the crybaby, respectively.  As of today, they're joining your class."--Guren to the Moon Demon Company classroom, Chapter 4, "The Worst Pair"
 * "Leave 'em. We won't get anything done in class with them conscious.  Right then.  The Cursed Gear aptitude test is coming up in a week.  It's been a while, but I guess I'd better teach you guys something, eh?"--Guren to the Moon Demon Company classroom after pulverizing Yu and Kimizuki, Chapter 4, "The Worst Pair"
 * "That doesn't matter. Strength alone is not enough.  Make friends.  Find companions.  Don't try to handle everything by yourself.  Because if you do... when the demon sinks its claws into you... it will swallow you whole, and you won't be able to come back.  Anger and impatience are a demon's favorite snacks.  As you are now... you'd be devoured by your own desires and turn into a demon yourself."--Guren to Kimizuki, Chapter 4, "The Worst Pair"
 * "I guess it's time I started making some preparations to steal the throne of this little kingdom out from under the main family."--Guren to Shinoa, Chapter 4, "The Worst Pair"
 * "Oh, I most humbly beg your pardon, General Tenri Hiragi. It's just that I was bored out of my mind."--Guren to Tenri Hiragi, Chapter 5, "Vampire Mikaela"
 * "Ugh! Dealing with idiots can be so exhausting.  Still...  Things are about to get a little more interesting."--Guren to Tenri Hiragi, Chapter 5, "Vampire Mikaela"
 * "If you're not strong enough, you die. That's the way the world works now.  We aren't holding hands and playing house here."--Guren to Sayuri, Chapter 6, "Black Asuramaru"
 * "Well, damn. I guess Yoichi wasn't quite strong enough after all.  Still...  A two-out-of-three success rate with the Black Demon Series is pretty good."--Guren to Yu and co., Chapter 6, "Black Asuramaru"
 * Okay, you two have your Cursed Gear now, so here's your first official Moon Demon Company mission. Yu.  Kimizuki.  Look at the ceiling.  There's a man-eating demon up there.  You two go kill it."--Guren to Yu and Kimizuki, ordering them to kill Yoichi, Chapter 6, "Black Asuramaru"
 * "YOICHI! Are you going to hide underneath that bed and watch your family die again?!  Get out of here and protect them!"--Guren to a possessed Yoichi, Chapter 7, "New Family"
 * "You have talent. But you feel guilty because you couldn't save your sister.  That's sapping your desire to live.  But today... you've found enough reason.  Your reason to live now... is to protect the ones who saved you today.  Your friends.  Revenge?  Don't let something so petty consume you.  That goes for you too, Moron.  Forget your old family.  Because you have a new family now.  Put your life on the line for the ones you see before you.  The past is gone.  There is only the future."--Guren to Yoichi, Yu, and Kimizuki, Chapter 7, "New Family"
 * "Sheesh. Raising kids is exhausting."--Guren to himself, Chapter 7, "New Family"
 * "Oops. I missed their commander.  Ah well.  Once we control this point, we'll have have won anyway.  Hey, Vampires!  Was all that human blood you drank today tasty?  Sure hope so... because that was your last supper.  Here we go.  Give me more power, Demon Blade: 'Mahiru-no-Yo.'"Guren's pre-battle speech, Chapter 11, "Queen's Contract"
 * "Oh ho! You're a strong one!"--Guren to Mikaela Hyakuya, Chapter 12, "A Very Safe Supplement"
 * "Over here. Checkmate, Vampire."--Guren to Mikaela Hyakuya after trapping him, Chapter 12, "A Very Safe Supplement"
 * "Thanks for your patience. Mind if I ask you to wait just a bit longer, though?  It's time for us to take our medicine, see.  Do you mind giving us, oh... another 20 seconds or so?"--Guren to Mikaela Hyakuya after reevaluating Mika and Ferid's strength, Chapter 12, "A Very Safe Supplement"
 * "So then, if I told you we're using him in our experiments, would you be angry? Humans are weak.  Fragile.  Now that the world has ended, what do we have to do to survive?  What do we have to do to kill vampires?  To eradicate the horsemen?  Your sister, Mahiru Hiragi, invented Cursed Gear.  How many people were sacrificed in that long process?  Without it... do you honestly think humanity would be able to survive?  Understand?  So quit spewing idealistic crap at me, Little Girl.  Or, what...  Are you falling in love with Yu?"--Guren to Shinoa about Yu, Chapter 14, "Everyone's a Sinner"