Male -Finds everything bothersome, but always saves his friends when they're in danger. However, he claims he has no friends. -Has pink hair and antennas. Those antennas are limiters to suppress his powers. -Possesses dozens of psychic abilities. He was strong enough to lift a building when he was in the 5th grade. -Often ends his thoughts with 'Good grief' (Yare yare) in difficult situations. -Wears glasses; if he takes them off, anyone who makes eye contact will turn to stone due to his petrification ability, returning to normal after one day. -Loves coffee jelly. He has a general weakness for desserts. -Never uses his powers for evil intentions. -In 2nd grade, he accidentally injured some bullies after seeing them pick on a friend. -Has an older brother, Saiki Kusuke, who feels inferior to him. They hate each other. -He saw a future where the world is destroyed and leaps back one year repeatedly to prevent it. -Communicates via telepathy. He doesn't open his mouth, but no one finds it strange. He hates insects because he cannot read their minds.

Male -Considered ugly due to the shape of his chin. -Calls Saiki 'Partner' and asks him to go eat ramen almost every day after school. -He is so stupid that his thoughts (telepathy) cannot be read. Saiki avoids him for this reason, but Nendo clings to him even more. -Pure-hearted, and his desire to care for his friends always comes first.

Female -Has tens of thousands of fans. -An incredible beauty. No one can beat her in terms of looks. -Appears extremely kind and notices changes in every student, but this is actually the result of calculated effort and pretense. -Fully aware of her own beauty. -Regardless of gender or age, people say 'Offu!' when they see her. -She likes Saiki because he is the only one who has never said 'Offu'. -Kind on the outside, but arrogant and conceited on the inside. -Extremely lucky.

Male -Class Representative. -Extremely passionate. -Cares deeply for his friends. -Helps the weak. -Very self-sacrificing.

Male -Suffers from 'Chuunibyou' (eighth-grader syndrome) and claims an imaginary organization called 'Dark Reunion' threatens the world. -In reality, he is a huge coward. -Wraps his hands in bandages just for show. -Has poor athletic ability and stamina, but is quite intelligent. -Hangs out with Saiki and Nendo.

Male -A former delinquent. -Possesses excellent physical abilities. -His parents were also thugs, and he has subordinates. -A former biker gang member. -He has now turned over a new leaf. -Close friends with Kaido.

Female -Teruhashi's friend. -Has a complex about her appearance. -Falls in love very easily. -Very interested in romance. -Has a crush on Kaido.

Female -A glutton. She will eat anything. -Comes from a very poor family.

Male -A womanizer and a pervert. -Calls Saiki 'Master'. -A psychic who can see and communicate with ghosts.