In order of importance, then appearance:

THE MAIN CAST

MIKE

Likes: Math, black, peace and quiet

Dislikes: Sunlight, large crowds

Secret Weapon: Earbuds

IKE

Likes: Reading, writing, D&D

Dislikes: Public speaking, the taste of his own foot in his mouth, spiders

Secret weapon: Charming awkwardness

CHARLOTTE

Likes: D&D, comics, Pokemon

Dislikes: Reasonable bedtimes, large arthropods, coconut

Secret Weapon: A sense of irony

SONIA

Likes: Magic: The Gathering, theater, the Internet

Dislikes: Calculus, shoes

Secret weapon: Poker face

WILBUR

Likes: Shakespeare, music, Magic: The Gathering

Dislikes: P.E., vegetables, smooth jazz

Secret weapon: Four-chord progressions

GWEN

Likes: Dancing, tea, reading, sewing

Dislikes: Confrontation, failure, coffee

Secret weapon: Handstands

THE BIT PARTS

JIRO YAMAMOTO

Mike’s long-suffering father. He’s a little clueless, but to be fair to the guy, he never expected to be raising this many teenagers at once.

SUZY YAMAMOTO

Mike’s twin sister. Their similarities ended in the womb, but they get along fine for the most part.

ANNA YAMAMOTO

Mike’s mother. Several other people’s mother as well. Works constantly and doesn’t have time to notice that she doesn’t have time to herself.

MS. NADIA FAROOQ

The Hawthorne Academy Humanities teacher. Dropped out of her Ph.D. program when she decided live teenagers were more interesting than dead writers.

MR. CHRISTOPHER ANDREWS

The Hawthorne Academy Civics teacher. Given to bad puns and pop culture references.

MS. RUBY CHEN

Headmistress of Hawthorne Academy. Knows your name and exactly what you did.

MS. TATYANA ALEXANDROVNA

Teaches ballroom dance at Hawthorne Academy and at her own studio downtown. Takes both equally seriously.

(More characters as they appear)