"Komi-san has a communication disorder." The protagonist. A student at Itan Private High School, serving as class representative from 1st to 3rd year. She is a tall, beautiful girl with long, straight black hair. She suffers from a severe "communication disorder" where she can barely speak to anyone outside her family, but she dreams of overcoming this to "make 100 friends." Her personality is introverted and timid. She is kind and cares for her friends. She has low self-esteem and is sensitive to others' reactions, often becoming shaken or flustered by words and actions, but she possesses a core strength that refuses to bend when it truly matters. She is well-bred and speaks in polite language to everyone except family. She has excellent grades and high athletic ability. Her hobbies include cooking and reading. She gives names to all of her stuffed animals. She loves cats, but they tend to avoid her.

"Tadano-kun is just an ordinary person." The deuteragonist. Class representative in 1st and 2nd year, and assistant class representative in 3rd year. A boy who is plain and "average" in every way, including appearance, grades, height, and weight. Conversely, he possesses a versatile talent for handling everything "normally." He is good-natured and a bit of a coward. He is a nice guy who treats everyone with politeness and kindness. He is excellent at reading the room and sensing others' feelings, which Najimi describes as the "ability to read minds." Due to his personality and skills, he is often saddled with work by others, but he also excels as a mediator and troubleshooter. His type is cool beauties with sharp eyes. First person: I (soft, polite). In his first year, he sits next to the school's Madonna, Komi. By interacting with her normally and without prejudice, he learns that she is actually a severe "communicator" who cannot even hold a conversation but desperately wants friends. Because of this, he becomes the first friend and confidant in Komi's life and school career, and thereafter assists her in making 100 friends.

"Najimi Osana is fitting in." Vice class representative from 1st to 3rd year. A person with phenomenal communication skills who can instantly close the distance and become close with anyone. They frequently organize spontaneous events and games of various scales. On the other hand, they hate studying, though their grades are relatively good. They are a pathological liar whose words and actions often don't match. They wear a boy's necktie instead of a ribbon. Perhaps due to frequent transfers, they are childhood friends with every student in the school, including Komi and Tadano. They attended the same middle school as Tadano and know all of his cringeworthy past secrets.