Kōhei Katsuragi

Appearance
Kōhei is a well built young man of above average height. He is bald due to an illness and has a large body frame compared to other students, which contributes to his intimidating appearance.

Personality
Kōhei is an intelligent student who worked very hard to reach Class 1-A that he became one of its representatives.

He is a serious man who adheres to the rules of manners and good conduct as he reprimanded another student of the class for making fun of Ken Sudō and his classmates. He was calm in telling Ken not to get easily provoked by his classmates' actions, but his demeanor intimidated him into stopping from arguing any further. From this display, it shows he is one of the few upper students who have no problems in associating with those of the lower classes or that he was simply annoyed by their antics.

He expresses slight anger when some of his failures are mentioned, such as when Kakeru Ryūen brought up his rejection after trying to join the Student Council.

Plot
Kōhei was first seen besides Arisu Sakayanagi listening to Manabu Horikita as he officially welcomes each first year student into the school.

Kōhei was next seen with Arisu along with several other students being congratulated and was asked the extent of what they know about the S-system.

He is next seen with Arisu looking at the scores of each class, remarking on the advancement of Class 1-C before following with a statement that Kakeru Ryūen is a dangerous man, to which Arisu simply responded by stating everything was "boring" and walks off.

During the school cruise, Kōhei was taking lunch at a fancy restaurant within the ship. He reprimanded Yahiko Totsuka (Kōhei's classmate) for inciting Ken Sudō, noting the possibility of bearing the consequence of losing points for bad behavior and to conduct himself a proper A-Class student should. Kōhei advises the Class D students to keep out of trouble. He then continues on by asking if Ken intends to repeat his earlier blunder, stopping the commotion from escalating.

After arriving on the deserted island, his class set up their camp inside a cave. He was spotted along with Yahiko conversing in front of the entrance by Kiyotaka Ayanokōji. Then sometime later, Kōhei appeared to confront Suzune Horikita and Kiyotaka, fending them off after knowing their intent to go inside their camp.

It was revealed that Kōhei had made a contract with Kakeru, unaware that he was being deceived in the process. Following that, on the last day of the survival test, Kōhei had an expression of disbelief after knowing that his class was ranked third, clueless that it was because of Kiyotaka's elaborate scheme. After that, Kōhei was assailed with voices of discontent by classmates complaining about their losses. Masayoshi Hashimoto came and commented about the outcome being pathetic.

Seemingly unfazed by the insult, Kōhei accuses him of being the one who told Kakeru the name of Class 1-A's leader(Yahiko Totsuka).

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Volume 4
After completing the grueling Island survival special test, yet another special test was announced back on the cruise ship. For this special exam, Katsuragi was placed in the Dragon Group, alongside prominent students from other classes like Ryūji Kanzaki from Class 1-B, Kakeru Ryūen from Class 1-C, and Suzune Horikita, Yōsuke Hirata, and Kikyō Kushida from Class 1-D. On the day when a briefing for each group about to start, Katsuragi was seen talking with Suzune near the door of the room, he praised her for her strategy during the island exam which bringing incredible results for Class D and declared that Class A would attack Class D without mercy next time. As the situation got serious, Kanzaki suddenly appeared, he told Suzune that Katsuragi only trying to get on her nerves and there's no need to waste her time on him. Katsuragi then reminded Suzune that she was just got lucky this time which didn't make them equals. Afterward, Ryuuen came up and walked over to Katsuragi and others, his appearance caused Katsuragi to grow grim as Ryuuen trying to provoke him by referring to Katsuragi as the beast from a little 'Beauty and the Beast' show that Suzune and Katsuragi were displaying. However, Katsuragi stayed calm in the face of that obvious provocation, instead, he struck back against Ryuuen's cavalier attitude with a sound argument before added that he wouldn't let Ryuuen bring his awful attitude to this exam.

During the first meeting of the rabbit group, it was revealed through Machida from Class A that Katsuragi actually had created a "castle gate" strategy for this special exam. Katsuragi proposed that since the VIPs had been distributed fairly amongst the groups, his plan was not to talk at all until the exam was finished so that there wouldn't be a traitor and allow the points to be equally distributed among the classes. In other words, he wanted to play defensively as if he was putting up barriers.

The following day, after the third discussion period ended, Katsuragi got confronted by Ichinose regarding Class A's strategy at the front of Dragon's room. Ichinose asked Katsuragi to reconsider his plan since they need communication to get through the test, adding that she knew Katsuragi had ordered his classmates to refuse to participate in the discussion. However, Katsuragi refused, stating that his strategy was made to protect his class. There were four possible outcomes in this test. As long as they chose one of those outcomes, it was legitimate. He wasn't interested in small group competitions; he was solely focused on maintaining Class A's lead. Ichinose tried to convince him to no avail. Katsuragi told her that she couldn't change his mind, and she would do the same if she were in Class A. If it was to protect their classes, they didn't particularly mind being criticized by others. After saying that, Katsuragi left.

Volume 4.5
On a certain day during summer break, Katsuragi was caught looking around at the shop by Kiyotaka and the idiot trio, who were there because they went to search for a present for their classmate. Katsuragi glanced around as if worried about something. As Kiyotaka thought that Katsuragi looked like someone thinking about stealing, he unconsciously grabbed his phone, presuming that if he had caught Katsuragi in the act, it could be useful later; however, he immediately rejected that idea. Katsuragi returned the thin box he held to the shelf, took down a similar item, then went through the same motions again, and seemed confused about what to buy. Ike noticed that Katsuragi came there to buy a present for someone and didn't want anyone to see what he was buying. Eventually, Katsuragi had made up his mind and picked a box of chocolates before making his way to the counter, with Kanji Ike and Haruki Yamauchi suspecting he had a girlfriend since the box was adorned with cute wrapping paper and ribbons. They then heard Katsuragi talking to the clerk about the chocolates being a birthday gift for someone on August 29.

At night, the usual group gathered at Kiyotaka's room, with the topic being Katsuragi. Kushida mentioned she didn't know of any girl with the same birth date as above. She also scolded Ike for calling Katsuragi a baldie. Apparently, Katsuragi had lost his hair completely when he was young due to illness. As the group discussed the possible candidate for Katsuragi's present, Kiyotaka wanted them not to interfere more in the matter, but the idiot trio refused before forcing him to investigate it.

The following day, Katsuragi was seen walking from the dormitory building after Kiyotaka had waited for thirty minutes at the crossroads. Katsuragi, while holding a shopping bag, wore the same attire he had on yesterday, which Kiyotaka found odd because the school uniforms did get extremely hot during the summer. Contrary to his prediction, Katsuragi headed towards the school building instead of the upperclassmen's dorms, which explains his uniform attire since entering the school building while wearing casual clothes was forbidden. As Kiyotaka couldn't follow along in his normal clothing, he went back to the shop where Katsuragi had picked out the present yesterday at the Keyaki Mall. He stood before the stacks of chocolate boxes with hearts design and such, trying to picture Katsuragi buying the gift for a man but he couldn't do it.

When Kiyotaka was in the middle of re-shelve the chocolate boxes after his elbow accidentally brushed them, Katsuragi suddenly appeared and asked what Kiyotaka was doing, he was still holding his gift bag. When Kiyotaka stammered that he came here to buy a birthday present, Katsuragi looked down at the scattered boxes, then bent and started picking them up. Ignoring Kiyotaka's words who refused the help, Katsuragi said that Kiyotaka didn't need to worry as the mess might make other customers uncomfortable so they should clean up quickly. They finished cleaning up before they knew it, and Kiyotaka thanked him. Katsuragi asked whether Kiyotaka was buying a present for his girlfriend. Kiyotaka denied it, explaining it was for his classmate's birthday before returning the question to Katsuragi. On being asked about his uniform, Katsuragi answered that he had been going to the school for some private matter. He talked to Kiyotaka about the disadvantages of attending this school, explaining further by stating that he didn't mean being divided into classes, but something that affected all students equally. As Kiyotaka couldn't answer, Katsuragi told him what he meant was the stipulation that you couldn't contact anyone on the outside and asked if Kiyotaka never thought to contact his parents or siblings. After some further exchanges, Katsuragi said that he was the kind of person who tends to agonize over things even if it was just a single present, saying that he couldn't make a snap decision when someone's feelings were involved, that's why he had been visiting the store three times. Thinking that questioning Katsuragi in a roundabout way would get them nowhere, Kiyotaka asked straightly about who the gift was for, to which Katsuragi dodged the question by replying it was personal. With that, Katsuragi headed back toward the dormitory.

Kiyotaka reported back his investigation, stating he still didn't know whom Katsuragi would give his present. Ike and Yamauchi suspected that Katsuragi bought the gift for himself, and started feeling sympathy for him. They then decided to give him a birthday present and celebrate his birthday tomorrow. Although Kiyotaka felt unsure about their conclusion, he chose not to refuse their idea.

The next day, Katsuragi couldn't hide his surprise as Ike and the group suddenly surrounded him. He confirmed that today was his birthday after Kushida asked him, though he was puzzled because he couldn't remember telling anyone his birthday. When Kushida said they wanted to celebrate it with him, instead of welcoming, he put his guard up, thinking that it was a trap laid by Class D. He stated they were not close friends and asking if there were any ulterior motives behind it. Although Ike showed his genuine sympathy that they really just wanted to celebrate his birthday, Katsuragi's mouth tightened before excusing himself as he had his own business at the school to take care of; he was still holding the birthday present bag from yesterday. When Ike pointed out how Katsuragi had been wearing his uniform a lot recently, Katsuragi glared so intently and demanded what he meant. Kiyotaka then helped Ike; he told Katsuragi he was the one who told Ike and others since wearing a uniform during summer vacation was unusual, successfully changed the topic.

When Katsuragi was asked why he was going to school, he still refused to answer and said it was nothing to do with them. However, Kiyotaka insisted something was bothering him because he had been holding the bag since they met at the store yesterday. Katsuragi finally answered he had some business with the student council, but unfortunately, they were out yesterday. After Kiyotaka mentioned that the student council room was being renovated until yesterday, Katsuragi noticed Kiyotaka had some connections to the council and requested Kiyotaka to accompany him, to which Kiyotaka agreed as he also happened to have some business with the council. }}

Abilities
Along with Arisu Sakayanagi, Kōhei is one of the leading figures of Class A and even has a faction following him.

Academic Abilities
Not much is known about his academic background, but it is presumed that Kōhei is one of the top-rankers of his class as he is one of its representatives.

Intellectual Abilities
Kōhei won Honami Ichinose's recognition when she reported him to Chie Hoshinomiya (her teacher), as someone to watch, along with notable figures from each class. This suggests he had enough abilities to pose a threat to Class 1-B.

Name Etymology

 * The name Kōhei consists of kanjis that mean "peace" (康) (kō) and "level, even, peaceful" (平) (hei).
 * Kōhei's surname Katsuragi consists of kanjis that mean "arrowroot; kudzu" (葛) (katsu) and "castle" (城) (ragi).

Trivia

 * Kōhei shared the same student identification number with Haruki Yamauchi.
 * For the 2nd year, his ID is changed to the same one as Sō Shibata's.


 * For the 2nd Year arc, when asked about his aspirations for the next year, he answered  'To temper myself. I'm ashamed of my immaturity so I want to become stronger. Not only physically, but also in spirit.'