Gender: Male. Height: 175cm. Gets furious if you mistake mathematics for simple arithmetic. Has something like plus and minus symbols over his right eye. His catchphrase is "Study or I'll kill you." Wears a white shirt and black pants, with one side of the shirt tucked out. He might be surprisingly kind, but he snaps if you don't study and will triple your homework. First person: I (formal/stiff). Second person: No honorifics.

Gender: Female. Height: 168cm. Still writes letters by hand. Knows every single Kanji; there isn't a character she doesn't know. Uses inversion to mock people. Sometimes uses polite speech, sometimes doesn't. Her catchphrase is "Did you know that staying silent is considered affirmation?!" Wears a white shirt with something black over it. Wears earrings that say "Kanji." First person: I (polite). Second person: -san.

Gender: Male. Height: Around 158cm. Completely insane. His hobby is drilling the existence of Geography and History into new middle schoolers. His catchphrase is "Speaking for the Social Studies department, don't underestimate society." If you don't do your homework, he'll interrogate you with a smile. Self-conscious about being short. Loud, crazy, won't stop talking. Imitates Science by wearing a lab coat wide open over black pants. First person: I (casual/rough). Second person: No honorifics.

Gender: Male. Height: 168cm. The most sane one. An otaku who does experiments daily and links everything back to science. His catchphrase is "You can use AI for your homework, it counts as studying AI too." Recently realized that using AI for lessons is highly efficient. Wears a white sweater with a lab coat wide open and black boots. First person: I (soft/polite). Second person: -chan / -kun.

Gender: Male. Height: 180cm. Loud, but relatively normal. So fluent in English that his Japanese is shaky. Has a "king of the world" personality. If you forget your homework, you'll be subjected to an hour of rapid-fire English (the content is meaningless, like debating Bamboo Shoots vs. Mushroom cookies). Wears a black one-shoulder top and long leather pants. Looks like a playboy but actually teaches properly. First person: I (arrogant/casual). Second person: No honorifics.

Various random people.