Daisuke is young man with with long brown hair, and has an arrogant expression on his face.
Daisuke often bully Hajime because of his jealousy to the attention that Kaori was giving towards him. After being teleported to Tortus, his bullying towards Hajime rises to a great extent by using violence and disguising it as a part of training. It also comes to the point of him attacking Hajime on the bridge, causing him to fall which resulted of him to become paranoid and tries to justify his actions. This became the start of Daisuke's descent into insanity, as he agreed to do what Eri said, both for his personal safety and for his desire to have Kaori.
He is also manipulative as he exploited Kaori's kind nature and Kouki's hero complex to have the rest of his classmates forgive him for nearly getting them killed to to his own mistakes. After Hajime survived and Kaori join Hajime's party, Daisuke feigning asked Hajime for "forgiveness" only for Hajime refused and not only calling Daisuke and his gang weak and worthless, but known of Daisuke's attempted murder on Hajime which caused Daisuke's insanity.
He was also shown to be a disloyal and selfish creep who only cares for himself and would be willing to abandon others when things get dangerous as he was willing to accept Cattleya's offer to join the demons side if meant for his survival.
After learning of Hajime's survival and obtained monstrous strength, he has became a coward when being terrified after Hajime murdered Cattleya as well tell Kouki that he will kill anyone including his former classmates after giving them a warning and desperate in having Hajime forgive him. However, He is terrified even more when Hajime exposed of Hiyama being responsible for his fall. He also became afraid and enraged at the fact that not only the once weak Hajime gained strength that was more powerful than his own, but he also lost Kaori in the process. This caused him to fall into insanity, as he was willing to take part in Eri's plan if it meant he could have Kaori, even going as far as to kill her himself so Eri could turn Kaori into his undead slave. For Hiyama's insolence, after Hajime beaten him up and toss him to the monsters to devour him.
Daisuke was the leader of the gang that constantly harass Hajime. Even after the summoning and the fact that he had superior stats than Hajime, the harassment became worse as he begun using violence during training sessions by disguising it as a part of their training.
During the their exploration into the Great Orcus Labyrinth, Daisuke tried to take a giant glanz crystal in an attempt to impress Kaori, but it turned out to be a trap and transported everyone to the 65th floor. They soon found themselves at a stone bridge and was trapped between a behemoth and and army of traum soldiers. At the end of the battle, he attacked Hajime while everyone was busy bombarding the behemoth and caused him to fall off the bridge. He later convinced himself that nobody was aware of his actions but eventually he was blackmailed by a fellow classmate and manipulated him by promising to give him Kaori as a reward if he help her with her plans.
Upon learning of Hajime's survival, Daisuke completely denied it until he saw Kaori cling to him. When Hajime killed Cattleya, Hiyama shown in fear and terrified of Hajime. His desperation grew when Kaori decided to join Hajime to stay by his side, but was unable to convince her otherwise. This resulted in him begging Hajime instead and asked him for forgiveness to comeback. However, Hajime refused his offer by subtly dropping hints that he knew who was the culprit behind his fall which left him in shock as Hajime and the others leave. Daisuke completely broke down afterwards but was reassured by Eri that he could easily get her back.
Daisuke participated on killing the kingdom's knights and was involved on killing the Knight Commander Meld Loggins. When the demons invaded the Heiligh Kingdom, all of the students discovered that Daisuke and Eri were traitors when Eri commanded her army of undead knights to subdue her classmates. Unfortunately, Daisuke's betrayal was not discovered until he murdered Kaori by stabbing her heart.
When Eri attempting to used her "Blind Soul" on Kaori's corpse, Hajime arrived and disabled her spell caused Hiyama to be angry. When began to fight, Hajime kicked Hiyama straight to the wall damaging his internal organs and breaking his bones.
He attacked Hajime with a fireball (but has no effect on him at all) and was later beaten by Hajime and throw to a group of demonic beasts, where he died after he was half-eaten alive by the demon army's monsters. Later, after the war in Heiligh Kingdom, Hiyama's dissected corpse was discovered and learn Hajime killed him which the so-called "Hero Party" to be terrified of Hajime only to reveal of Hiyama's betrayal.
- Reichi Kondou, Yoshiki Saitou & Shinji Nakano - his three former friends and partners in crime. Alongside them, he would bully Hajime as much as possible mostly because they liked Kaori as well from the past. But now they are terrified of Hajime after he murdered Cattleya not only his monstrous strength and ruthless but lost Kaori in process due to her love for Hajime alone. However, in truth, Hiyama doesn't care of his "friends" as they are nothing but merely tools in order to claim Kaori for himself and betrayed them when he let Eri killed Kondou. After Hajime killed both Kondou and Daisuke, two of Daisuke's so-called "friends" Nakano and Saitou were terrified to cross Hajime and not wanted to met the same fate as Daisuke when they apologized to Hajime and will never get in his way or harming his comrades (harem) including Kaori.
- Eri Nakamura - one of his fellow classmates and his fellow traitor. After she discovers that Hiyama was the one who discovered that he (almost) killed Hajime which turn him into a monster as she uses this knowledge to blackmail him into working with her.
- Ehit: Though not meet face to face, Ehit is amused of Daisuke. Daisuke works for the god along with Eri to kill all of his classmates and reanimated them as their undead slaves.
- Hajime Nagumo - Daisuke's former bully victim from the past, but now his direct murderer. Daisuke hated the fact that Kaori was interested in Hajime and not him so he decided to make Hajime's life as miserable as possible. This would later escalate to physical violence after they were transferred to Tortus and Daisuke obtained a strong combat job compared to Hajime's non-combat job. It would escalate to attempted murder after he saw Kaori coming out of Hajime's room one night. Later, after finding out Hajime had survived the fall into the abyss, he begins to feel scared and intimidated that his plan will be exposed and witnessing Hajime's monstrous strength. After Hajime murdered Cattleya, Hiyama is terrified of Hajime of his demonic powers and ruthlessness. When witnessing Hajime tell Kouki of he will kill him even if they were classmates, Hiyama shown in greater fears . When Kaori chose to travel with Hajime, he became desperate along with his gang pleaded Hajime to join the Hero party (just so he would be closer to Kaori) while feigning an apology for the treatment they gave him in the past but in response Hajime gave him some hints that he knows what happened, subtly warning Daisuke to stay out of his way if Daisuke wished to stay alive. Later on, after he killed Kaori and Eri's attempted "Bind Soul" failed, because of Hajime's arrival, Daisuke becomes mad and attacks Hajime with a fireball (but has no effect on him) while badmouthing Hajime for Daisuke's own failure to make Kaori his, but that only enraged Hajime even more as he brutally thrashed Daisuke as he breaks almost all of Hiyama's bones and damaged his internal organs. When Daisuke was bragging how he will kill Hajime and make Kaori his one day, Hajime put out of Daisuke's misery after threw him into a group of demons where he was left to be eaten alive and Hajime watch pitilessly and Daisuke was screaming as Hajime got revenge of Daisuke for killing Kaori but not caused Hajime fell to the bottom abyss.
- Kaori Shirasaki - Daisuke was shown to be deeply in love with Kaori to the point where he would do anything jut to obtain her but failed due to not only Hajime's survival, but his monstrous strength as well. He was even willing kill her so that Eri could turn her body into an undead puppet who would listen to his every command but failed due to Hajime's arrival. Hajime killed Hiyama to only avenge Kaori. After Daisuke's death and Kaori's revival, Hajime revealed to her of Daisuke's betrayal and had killed him.
- Other Classmates - most of the other classmates ignore Daisuke bullying Hajime. But in truth, Everyone hates him and his gang deeply for their selfishness lust for Kaori and bully many people including Hajime. After Hajime's alleged death, they show their more animosity towards him since it was his actions that transported them to the labyrinth floor where it took place. Though when Hiyama put up a false act of remorse in front of Kouki and Kaori, they readily forgave him due to Kouki's misguided justice and Kaori's immense, kindness as well as their overwhelming popularity with their classmates, with the exception of Shizuku, who had some doubts about Hiyama's deception and manipulation, though she chose to put aside it for the sake of looking out for her closest friends. After his betrayal was revealed, as well his desire to turn Kaori their beloved class idol into his undead slave, it left an immense and permanent negative impact on all of his classmates, particularly Kaori's closest friends, Shizuku, Suzu, Ryuutaro, and most of all Kouki, who had place misguided trust in Hiyama. When Kouki furiously accused and blamed Hajime for not warning them of Ehit's schemes earlier in the Orcus Dungeon that had allowed Eri and Hiyama to betrayed them, Hajime coldly stated it is their careless optimism and delusional idealism at fault that they had nearly died and reminded them it is precisely their ridiculously naive expectations that fellow classmates must always help and protect each other is what had allowed even an idiot like Hiyama to manipulate and backstabbed them without even realizing it, a fact that all of them could not deny. Having personally witnessed Hiyama's horrific fate of being brutalized by Hajime before being thrown to be eaten alive by monsters served as a strong warning of the terrifying extends of Hajime's savage brutality as they are terror stricken of being subjected to the same fate as Hiyama if they dared to cross Hajime or harming his comrades (harem) including Kaori, even Kouki despite his dedication to justice and disgust of Hajime's cold and pragmatic disregard for morality did not have the courage to completely go against Hajime due to his immense power and ruthlessness. After they were given by Hajime's warning, they still held bitter memories of how they hated Daisuke for what he have done while back in school and Tortus.
Weapons & Equipment
- Longsword - his main weapon since being summoned to Tortus. It was broken during his fight with Hajime when the kingdom was invaded by demons.
Powers & Abilities
- Enhanced Physical Abilities - being one of the summoned heroes, Daisuke was blessed with superhuman physical abilities than an average human in Tortus. But his strength is now inferior to Hajime's demonic strength after the latter devoured many powerful monsters.
- Enchanced Stamina - Though Daisuke lack of durability, he has enough endurance to barely speak after coughing out blood when he got brutally injured as when he had almost all of his bones broken and his internal organs took major damage by Hajime.
- Expert Swordsman - Daisuke was shown to be skilled and proficient in using sword due to his job as Light Warrior. Combined with his enhanced physical abilities, Hiyama was able to secretly and easily kill all the knights and soldiers of the Heligh Kingdom, including the Vice-Commander Jose Rancaid who is a great master swordsman and the second strongest knight after Meld in order for Eri to reanimate them into their undead puppets. Eri herself had enough confidence in Hiyama's abilities to subdue a badly injured and weakened Kouki should he ever break free and retaliate during her death trap. However, he lacks technique and real combat experience as he is too weak against Hajime.
- Sword Art - a skill that increase efficiency in using a sword.
- Wind Magic Affinity - it allows the user to use wind magic at a capable rate.
- Language Comprehension - a base skill granted to all those who got summoned. It gives the user the ability to understand any language and be proficient in it.
- Fireball - one of the most basic Fire Spells. However, his fireball is too weak against a very powerful individuals as if it didn't do anything on them such as Hajime who gained power by devouring many powerful monsters.
- (To Hajime Nagumo his last words) "I’ll kill you! No matter what ish takesh, I swear I'll kill you!"
- Daisuke was the fourth member of his class to be killed, but the only one to be killed by either the demons or their monsters (Hajime knocked him towards a group of approaching monsters).
- Hiyama’s family try to get revenge on Hajime but got their hearts broken by him.