Aika Natsukawa is the heroine of "The Dreaming Boy is a Realist" and is a school idol known for her stunning looks. She has a serious personality, a strong sense of justice, and is a bit stubborn. She used to reject the protagonist, Wataru Sajo, as "annoying" during his relentless advances, but when he suddenly starts keeping his distance, she conversely begins to feel bewildered and lonely. She is actually very clumsy with her emotions and has a charming "tsundere" side, unable to be honest about her feelings. As her relationship with Wataru changes, her delicate heart gradually begins to take notice of him.

Kei Ashida is a cheerful and caring high school girl who is a good friend and confidant to the protagonist. She observes her surroundings well and sometimes smooths over human relationships with precise advice. She possesses a social nature that makes it easy for her to get along with anyone, and she plays an active role as a presence that softens the atmosphere of the story.

The protagonist's older sister, she is a woman with a calm and mature atmosphere. While she cares for the protagonist, she also shows a composed demeanor, occasionally teasing him. She has high insight and calmly assesses the situations around her, depicted as a presence that gives the story a sense of security and depth.

A middle school girl characterized by her gentle and modest personality. She is well-liked and considerate of those around her, making her a trusted figure in her class. Although she isn't the type to express her feelings strongly, she possesses both inner strength and kindness, playing a role that adds warmth to the story. However, when the topic turns to Wataru Sajo, her personality shifts into that of a yandere.

He harbors intense feelings for the heroine, Aika Natsukawa. He possesses an incredibly strong mental fortitude, never losing heart even after being rejected by Aika countless times. Because he persistently presses Aika for a relationship, he has been labeled a stalker within the school, but since he is not a bad person at heart, he has a normal amount of friends.