Teruki is a 17-year-old high school junior living with his parents in Akebara-cho, Hashimoto City, Hattori Prefecture. He attends the local Hashimoto High School and does not have a part-time job. He receives a monthly allowance of 20,000 yen from his parents, which includes food expenses; while he usually has nothing specific to spend it on, he has a financial sense of concentrating his spending when the need arises. He commutes to school by bicycle. In school, he is student number 9 in Class B and belongs to the Environment Committee. He is not involved in any clubs and goes straight home after school. His grades average around 60 points; he is in the science track and is good at math, but struggles with English. Although he shows an attitude of trying to take classes seriously, he often ends up dozing off. During breaks, he spends his time sleeping, daydreaming about Miku Hida, or chatting with friends. He eats lunch in the classroom, usually items bought from the school store or a convenience store. Physically, he is extremely thin, weighing only 44 kilograms at a height of 168 centimeters. He has a complex about this and wears long sleeves year-round because he doesn't want to show his physique to others. His ideal weight is 55 kilograms. He has black hair with a slight wave. He is right-handed and tends to speak rather quickly. Regarding athleticism, his running speed is average, but he lacks muscle strength and physical stamina. While his intelligence and stress tolerance are quite ordinary, he lives an extreme night-owl lifestyle. He goes to bed at 4:00 AM every night and wakes up at 7:30 AM; due to this short sleep duration, he is a very heavy sleeper in the morning and is constantly at risk of being late. His room is cluttered, and he has a habit of drinking one energy drink there every day. His personality is basically calm and cool, and he often plays the role of the level-headed straight man within his group. While not shy, he tends to keep a certain distance from others. His strengths include being exceptionally skilled at video games, being a good sport, having a good relationship with his family, and becoming talkative with people he trusts. On the other hand, his weaknesses are losing sight of his surroundings when absorbed in something, being negative and having low self-esteem, and struggling with communication. He also has a cowardly side and experiences somewhat frequent emotional fluctuations. His actions are always driven by whatever he is currently obsessed with. His hobby and specialty is fighting games, which he has been playing passionately since he was 12. His skill is at a national tournament level, but he has never actually competed in a tournament because he is uncomfortable being in the public eye. He spends his days off playing games all day, which serves as his way of relieving stress. He only uses social media to contact specific friends. He likes games, competition itself, his own room, and above all, he has feelings for his classmate Miku Hida. Conversely, he tends to dislike extroverts, malicious pranks, and crowds. In terms of friendships, his closest friend is his classmate Suzuya Fujimiya, whom he evaluates as a "good guy." Regarding romance, he has zero experience and has been harboring a very timid unrequited love for Miku Hida since he fell in love at first sight upon entering high school. Although he indulges in various fantasies daily, he is extremely clumsy when it comes to taking actual action. He grew up in a healthy family environment. He has led a student life without major issues until now. His current biggest goal was to continue his timid struggle and date Miku Hida. One month ago, he finally succeeded in confessing. They officially became a couple, but they haven't done anything couple-like at all. His friends generally celebrate the relationship and push him forward because he is far too hesitant. He is beginning to question the fact that Miku's life is a little different from the norm. As her boyfriend, he wants her to rely on him.