Kousuke Endou/Chronology

Biography
Kousuke was born the middle child of his family. Due to his thin presence, he tended to be unintentionally ignored by his friends and family, but was still loved by them. He would constantly be left behind on family trips and school trips throughout his childhood. During one time in middle school, when he confessed to a girl he liked, she responded by not even knowing that he was in her class. This caused Kousuke to shut himself in his room for some time.

During his second year of high school, Kousuke and his entire class was summoned to Tortus to aid humanity in their war against the demons. Kousuke was given the vocation of Assassin. After his fellow classmate Hajime Nagumo fell towards his apparent death in the Great Orcus Labyrinth, Kousuke was one of few students that decided to continue their regular training. He was tasked with scouting ahead to predict the strength of the labyrinth's monsters before the rest would come in and attack.

When Kousuke and the other students reached the 90th floor of the labyrinth, they were confronted by the demon Cattleya and a small army of monsters under her control. The students tried to fight her, but she had forced them to retreat to the 89th floor and hid themselves in one of the rooms. Everyone wished for Kousuke to retreat to the teleport gate on the 70th floor that was guarded by captain Meld Loggins and inform him of the situation. Kousuke was chosen specifically due to his weak presence, combined with his assassin skills, made him the most likely to escape without being noticed. Kousuke knew that it would be impossible to get help and that the reason they wanted him to flee was so that he could survive, but he was still determined to save his friends. He managed to reach Meld and the other five knights that were guarding the 70th floor, but Meld felt he would just slow him down and offered Kousuke some healing medicine instead. Meld also ordered Kousuke to prioritize saving Kouki over the other students since he was humanity's chosen hero. Just then, they were attacked by Cattleya and her monsters. Meld ordered Kousuke to retreat via the teleport gate and destroy it so that the monsters would be unable to follow him. Knowing full well that Meld would die, Kousuke followed his orders and escaped. He arrived at the 30th floor via the teleport gate, but was unable to destroy it due to the knights that were guarding it. Unaware of the situation, they pilled him to try and stop him from destroying the gate. It was then that one of the monsters teleported to the 30th floor and started killing everyone. Kousuke managed to kill the monster, but not before it killed all the knights, as well as severely wounding him in the process. Kousuke used one of the medicine vials that Meld gave him and hurried to the surface for help.

Kousuke arrived at the Adventurer's Guild in Horaud in order to find help, but none of the adventurers wished to go with him after hearing of how bad the situation was. Kousuke's frantic behaviour caused him to be escorted by Branch Chief Loa Bawavis to his office. Soon afterwards, Kousuke ran back to the guild hall after discovering that his classmate Hajime Nagumo was still alive and at the guild. Kousuke was unable to recognize him at first due to his transformation, but soon realized that it was him. Kousuke tearfully pleaded for Hajime to rescue their classmates. Taken aback by this sudden outburst, Hajime did not know how to respond, but Loa arrived and recommended that they continue their conversation in his office to prevent a panic among the adventurers. After explaining the situation in detail, Kousuke hoped that Hajime would help, especially after discovering how strong he had become. To his surprise, however, Hajime was not interested in saving his classmates and had treated them with total indifference. Hajime soon changed his mind after learning that his classmate Kaori Shirasaki was still alive, and eventually decided to help them in order to save her to repay her kindness. Kousuke and Hajime returned to the labyrinth and Hajime managed to save Kaori and Shizuku from Cattleya's most powerful monster by using his pile bunker to drive a metal stake down the various floor ceilings until it reached the 89th floor. As Hajime was obliterating Cattleya's monster army with ease, Kousuke told everyone that it was Hajime that had come to help them. Everyone couldn't believe that the person who they previously labelled as worthless was effortlessly killing off the same monsters that pushed them to the brink of death. The one who was shocked the most by this revelation was Daisuke Hiyama and was freaked out to the point that it scared Kousuke a bit. Hajime soon killed Cattleya and all of her monsters and escorted the students back to the surface.

After Hajime departed from his classmates, along with Kaori, the students continued their training. One night, Kousuke slept through dinner and no one remembered to wake him up. He went to the kitchen to get some food and managed to obtain some vegetable scraps. Unfortunately, it upset his stomach and he had to use the bathroom. After two hours of getting his stomach under control, Kousuke ran into Meld and nearly spooked him to the point of attacking Kousuke. He explained to Meld about what had happened to him (including the fact that he had a difficult time finding toilet paper), but Meld just told him to get some rest and watched him off. Due to his recent food episode, Kousuke did not notice that Meld was acting more nervous than usual.

When the demons invaded the Heiligh Kingdom, Kousuke and the rest of the students were ambushed by a legion of undead knights that were under the control of Eri Nakamura. It was then revealed that Captain Meld was among her minions and that he had been killed before the invasion. Kousuke was the most badly injured out of all the students after they were ambushed. Swords were sticking out of not just his back, but his limbs too. As a result, he had lot a lost of blood and was on severe pain. Eri planned to kill all the students and turn them into her undead minions, but she was stopped by Hajime and managed to repel the invasion. After the demons were defeated, Kousuke felt bad about the death of Meld and secluded himself in his room for some time. He blamed himself for not noticing a change in Meld's behaviour and believed that he could have helped him since he was the last person to see him alive before he was killed.