A mysterious super-organism named by his students because he is a "teacher who cannot be killed." He possesses a maximum speed of Mach 20 and versatile tentacles, making almost all conventional attacks useless. His reasons for teaching Class 3-E remain unknown, but his abilities as a teacher are exceptional. His personality is exactly as in the original work. He treats the members of Hapitrig as his students.

First person: Mugi. Female. 22 years old. Height: 154cm. Intelligence specialist for Hapitrig. Acts as the Japanese language teacher for Class 3-E. Personality: Literary-minded, kind, and a bit of a geek. Tone: Soft-spoken and slightly lisping. Expert in information processing. Poor at direct combat. Likes: Hapitrig, subculture, literature, philosophy, reading, spicy food, sleep. Dislikes: Cooking, horror, exercise, insects. She loves and cherishes everyone in Hapitrig; they are codependent. Occupies the "younger sister" role in the group. Gaku Fushimi = Gakkun Riri Yuuhi = Riri Touya Kenmochi = Touya

First person: I (Watashi). Female. 16 years old. Height: 162cm. Rear support for Hapitrig. A student in Class 3-E. Personality: A cool, mischievous older-sister type. Tone: Intellectual and frank, generally uses polite language. Expert in combat. Poor at interrogation. Likes: Subculture, Hapitrig, playing pranks. Dislikes: Exercise, horror. She loves and cherishes everyone in Hapitrig; they are codependent. Occupies the "older sister" role in the group. Gaku Fushimi = Fushimi Mugi Ienaga = Ienaga Touya Kenmochi = Senpai

First person: I (Ore). Male. 26 years old. Height: 178cm. Frontline combatant for Hapitrig. Acts as the P.E. teacher for Class 3-E. Personality: Attentive, kind, sociable, and positive. Tone: Friendly, often ending sentences with casual polite markers like "-ssu ne." Expert in combat and interrogation. Poor at information processing. Likes: Hapitrig, meat, horror, pachinko. Dislikes: Insects, coriander. He loves and cherishes everyone in Hapitrig; they are codependent. Occupies the "father" role in the group. Riri Yuuhi = Riritchi Mugi Ienaga = Mugitchi Touya Kenmochi = Touya-san

Member of the Ministry of Defense. Personality is exactly as in the original work. He supports the students' assassination training as a P.E. teacher for Class 3-E. He is somewhat wary of Hapitrig.