; : :The narrator of the light novels. He is a first-year high school student who used to be delusional, calling himself the "Dark Flame Master" while in junior high and becoming alienated from everyone as a result. He attempts to bury his past by enrolling in a high school far away from his junior high classmates. However, after encountering Rikka, his past delusions come back to haunt him. He ends up joining the club and becomes friends with Rikka's cohorts as well as school beauty Shinka Nibutani. He and Rikka eventually become closer and start dating. In the anime film, Yūta gives Rikka a ring to show "proof" that he will stay with her. He and Satone Shichimiya were also classmates in junior high and she was the one who inspired him to become the "Dark Flame Master". A
running gag in the anime series shows him hitting Rikka on the head with his hands or any objects. ; : :Yūta's classmate and neighbor residing above the apartment. She is an intensely delusional girl who believes herself to possess a , and as such always wears a
eyepatch over her right eye and wrapped bandages around her left arm without injuries. Despite being quite attached to Yūta, she is cautious of strangers and adopts a battle pose whenever she meets someone for the first time. Her fantasy weapon of choice is a frilly parasol which she wields as a sword. For her delusional operations, she often dresses in a mostly-black gothic dress. At school, she wears a uniform with a frilly skirt, long black knee socks, and
roller shoes. She is also rather clumsy, often tripping over and forgetting things. The origin of her delusions came from her father's death three years prior, where she was forced to live with her father's family until she moved in with her sister. They also come from Yūta himself, when she saw Yūta in his delusional phase at the balcony above the apartment. Although initially finding each other annoying and unreliable, they eventually develop feelings for one another and start dating, but Rikka's delusions appear to keep their relationship from progressing. A
running gag in the series reveals that she visits Yūta by descending a balcony with a rope. ; : :Yūta's classmate and one of the most popular girls in the class. She is the class representative and a member of the cheerleading club. She wears a hairclip on her bangs. Although Shinka is generally thought of a kind and gentle girl, she is later revealed to be a former
chūnibyō by the name of and had also chosen a different high school from her previous classmates to escape her past. In the anime series, when she learns Sanae is in possession of the
Mabinogion, a blog penned by Shinka during her chūnibyō phase, she joins Rikka's school club in order to try and retrieve it, but gives up when she learns that Sanae has kept multiple backup copies. When out of the public eye, Shinka shows her true nature to be bit more bitter and easily irritable, particularly when dealing with Sanae, but they eventually care for each other and she is genuinely a kind-hearted person who loves and cares about her friends, and she will help them if needed. She later quits the cheerleading club to focus more on making herself popular. ; : :An anime original character. She is a carefree girl who is a year above Yūta and the others. She loves sleeping and often carrying around a pillow with her wherever she goes. In one extreme case, she is even shown sleeping in a full futon on school grounds. Having been home-schooled before high school, she is very sheltered and conservative, lending her an old-fashioned ladylike demeanor which Makoto finds attractive. Her own "Nap Club" is integrated into Rikka's social group for lack of members. She earnestly attempts to understand Rikka and Sanae's delusional fantasies. She has a tendency to
sleep-talk. She is also quite fond of cats and often naps curled up like a cat. ; : :An anime original character. She is Rikka's best friend. She is a third-year junior high student with a long blonde elastic
twintails that often prove to be more of a hindrance than a help. Like Rikka, she is extremely delusional and often indulges in fantasy with her. Unlike Rikka, she is a superb student who is at the top of her class and has already completed the entire junior-high mathematics curriculum. She owns several copies of a spell book which is the remaining evidence of Shinka's delusional days. She is often at odds with Shinka, whom she does not believe to be the real Morisummer. In the Japanese dub, she often ends her sentences with 'desu', emphasizing it to make it sound more like 'death'. She dislikes dairy products, even though she is forced to drink the milk and grow tall. She is aware that her delusions are nothing more than delusions. She comes from a very rich family and tends to behave normally around her classmates. She later promotes to the high school where Yūta and friends are studying. ; : :Yūta's classmate who becomes interested with other girls at school. He joins the Light Music Club so he could be with girls and attract their attention by carrying about his guitar, though he does not seem to have learned how to play it. Fond of his thick hair after being forced to wear it short for sports activities for the last three years, he is forced to have his head shaved once more when his notebook containing the "Cutie Poll" of the girls in his class is discovered. In the anime, he develops a crush on Kumin after she becomes fond of petting his
buzz cut hair. ; : :Yūta's younger sister attending the first year of junior high school. She is mature for her age. ; : :Yūta's youngest sister. She finds Yūta's prior fantasy antics intriguing, often refers to them as "cool" and admires or idolizes Rikka. ; : :Yūta and Rikka's homeroom teacher. She is often kind, if sometimes a little sadistic in teasing her students, particularly Rikka. She is called "Nana-chan" by Yūta and Rikka. ; : :Yūta's former junior high school classmate. She first appeared in the second light novel and the anime's second season. She is depicted as having a cheerful, fun-loving personality. Although she considers Yūta to be her best friend, she ended up transferring schools without saying goodbye during their second junior high school year. She transferred to Shinka's junior high school where they became close. She suffers from delusions, calls herself , and addresses Yūta with the nickname . Yūta and Shinka's delusions began with their admiration, and mimicry of Satone's behavior. During her time with Yūta in junior high school, she developed feelings for him, but chose to push those feelings aside and stay as "Sophia Ring SP Saturn VII" and the "Magical Devil Girl" forever. She makes Rikka jealous sometimes when she shows affection for Yūta. ; :An upperclassman of Rikka and Yūta. She is a main character in the third light novel. She attends the Eccentric Drama Club. ; : :An anime original character and Rikka's older sister. She supports her becoming a chef at a fine restaurant. She often has to put up with her younger sister's delusional antics, often punishing her by whacking her with a
ladle. She is also seen to be extremely acrobatic and flexible, which she attributes to being a rhythmic gymnast when she herself was in high school. Rikka depicts her sister as a high priestess of evil and accuses Tōka of restraining her from her quest to reach the "Invisible Boundary Line". In one instance, she was playing house with Yūta's youngest sister Yumeha, but had a negative outlook where they divorced. ; : :Yūta's classmate from the novels and the class idol. She was in second place in Makoto's ranking of the most beautiful girls in his school, although still remains the centre of attention. She had a close relationship with Shinka in junior high school. ==Media==