|Affiliation||Advanced Nurturing High School|
|Private Point||382355 (history)|
|Light Novel||Volume 3|
|Manga||Volume 4, Room 17|
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.
Kōhei is an intelligent student who worked very hard to reach class 1-A and 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.
Along with Arisu Sakayanagi, Kōhei is one of the leading figures of Class A and a faction even dedicated to him.
Not much is known about his academic background, but it is presumed that he's one of the class top-rank as being one of its representatives.
Kōhei won Honami Ichinose's recognition when she reported him to her teacher, Chie Hoshinomiya, as someone to watch, along with notable figures from each class. This suggests Kōhei having enough ability to pose a threat to class 1-B.
Kōhei was first seen besides Arisu listening to Manabu Horikita as he officially welcomes each student to 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 makes another appearance again with Arisu looking at the scores of each class, remarking the advancement of Class C before following with a statement that Kakeru Ryūen is a dangerous man, to which Arisu simply responded by asking how boring it is.
During the cruise, Kōhei was taking a lunch at a fancy restaurant within the ship. He reprimanded Yahiko Totsuka 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 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, at the last day of the survival test, Kōhei showed an expression of disbelief after knowing that class 1-A ranked only in third place, clueless that it was because of Kiyotaka elaborate scheme. After that, Kōhei was assailed with voices of discontent by fellow classmates complaining about their losses. Masayoshi Hashimoto came and commented about the outcome being pathetic. Seemingly unfazed by the insult, Kōhei accuses him as the one who told Kakeru the name of class 1-A's leader.
- He shares the same student identification number with Haruki Yamauchi.
|Homeroom Teacher||Tomoya Mashima|
|Class Representatives||Arisu Sakayanagi • Kōhei Katsuragi|
|Students||Masumi Kamuro • Yahiko Totsuka • Masayoshi Hashimoto • Takurō Morishige • Kōji Machida • Shigeru Takemoto • Shinji Matoba • Ryōko Nishikawa • Koharu Yano • Kenta Yoshida • Haruka Nishi • Naoki Shimizu • Yasumi Sawada|
|Members||Yahiko Totsuka • Kōji Machida|