Assassination Classroom Wiki


— Koyama's signature laugh

Natsuhiko Koyama (小山 夏彦 Koyama Natsuhiko) is a student in Class 3-A in Kunugigaoka Junior High School and the president of the Biology Club who is one of the Big Five


Koyama wears black framed glasses and appears to have crooked teeth. His hair are black, long, and shaggy, giving him a disgruntled look. His face is often contorted with an overly large smile and squinted eyes, accentuating his strangeness.He also looks to have a unibrow. Also with uneven teeth.


Koyama is not different from the rest of the Five Virtuosos in terms of behavior and temperament. He, like most other people in the main campus, looks down on the E class students and he is constantly frustrated when beaten by them. He is an extremely intelligent person and excels in science, despite being constantly beat out for the top spots.



Memorization: Koyama claims to have memorized every chemical formula in preparation for Kunugigaoka Junior High School's exams. His abilities are lampshaded further in Koro-Q, where he claims to have memorized every monster listed in the monster encyclopedia.


  • (About Gakushu Asano) "Being honest; he could do many things he finds gross."


  • The name Natsuhiko means "summer" (夏) (natsu) and "boy, prince" (彦) (hiko). 
  • Natsuhiko's surname Koyama means "small" (小) (ko) and "mountain, hill" (山) (yama). 


  • The character book [1] describes Koyama's middle school life as unpleasant until he meets Gakushu Asano, who tells him “With your strength, you should more boldly look down on others". Thanks to that, Koyama became much more confident, unfortunately to the point of being egotistical, but he feels a strong obligation to Asano because of this.
  • According to the Graduation Album [2], Koyama later finds employment at an unnamed pharmaceutical company.
    • While working there, he chopped off his long hair because it got in the way while developing new drugs, which awakens him to the call of beauty. He ends up not only straightening his teeth, but even goes as far as to get a mandible reduction. He might be a hottie now.



e - d - vKunugigaoka Junior High School
Class 3-E
Faculty KorosenseiTadaomi KarasumaIrina JelavićAguri Yukimura
Students Masayoshi KimuraHinano KurahashiYuma IsogaiHinata OkanoHiroto MaeharaMeg KataokaKotaro TakebayashiToka YadaKoki MimuraRio NakamuraNagisa ShiotaKaede KayanoTaisei YoshidaYukiko KanzakiTaiga OkajimaRinka HayamiTomohito SuginoYuzuki FuwaTakuya MuramatsuKirara HazamaRyunosuke ChibaManami OkudaSosuke SugayaSumire HaraRyōma TerasakaKarma AkabaneItona HoribeRitsu
Main School
Faculty Gakuho AsanoKiyoshi Terai
Students Tomoya SeoTeppei ArakiNatsuhiko KoyamaRen SakakibaraGakushu AsanoKaho TsuchiyaKazutaka ShindōKokona TagawaNobuta TanakaChousuke Takada