Asahi Naruhaya is a former participant in the Blue Lock project and was a member of Team Z. He is a sixteen-year-old high school student with a small build, standing at 168 centimeters tall, which is quite short for a soccer player. His appearance is characterized by fluffy, caramel-colored blonde hair, darker round eyebrows, and long eyelashes. He is the second of six siblings, with one older sister named Mahiru and four younger siblings: Sena, Yuya, Yota, and Tenka. Before joining Blue Lock, he played soccer for the Kanou Gakuen high school club. His background is marked by significant hardship, as he lost both parents in an accident approximately two years before the story begins. This tragedy left him as a primary caretaker for his family, forcing him to work multiple part-time jobs while continuing to practice soccer and manage household chores, often sleeping only about four hours per night.

Naruhaya has a complex personality that blends a mischievous, playful side with a deep sense of responsibility. Within Team Z, he often acts as the jokester, engaging in antics like stealing food from his teammates. Despite this lighthearted exterior, he is a kind and caring individual, demonstrated by actions such as tirelessly searching for a lost hair tie belonging to his teammate, Gin Gagamaru. His most defining trait is his profound self-awareness. He clearly recognizes his own weaknesses and limitations as a soccer player, especially when compared to naturally talented "geniuses" like Seishiro Nagi, Shoei Barou, and Meguru Bachira. This realism extends to his view of himself and his friend Yoichi Isagi as "ordinary" players who cannot compete on equal terms with such prodigies. This awareness is not born of self-pity but from an honest assessment of his abilities, which he considers his greatest strength.

Naruhaya's primary motivation for joining the high-stakes Blue Lock program is not fame or glory for himself, but the welfare of his family. He dreams of becoming a professional soccer player and a member of the Japanese national team to earn enough money to lift his family out of poverty. His position as one of the eldest siblings drives him to succeed, and he carries encouragement written on caramel candies from his family as a good luck charm. His life motto is simply "Happy," which he likes for its positive energy. This powerful, family-oriented motivation gives him a strong ego and a determined spirit to survive in Blue Lock's harsh environment.

Within the story, Naruhaya is introduced as a member of the initially struggling Team Z during the First Selection. He contributes as a forward and a defender, using his specific skills to help the team survive. He successfully advances to the Second Selection, where his rank improves from an initial low position. During this phase, he partners with Shoei Barou for a crucial 2v2 match against Yoichi Isagi and Seishiro Nagi. Before the match, he articulates the stakes to Isagi, acknowledging that they are putting their dreams on the line. Throughout the match, he demonstrates his tactical understanding but is hampered by Barou's refusal to cooperate. Ultimately, his team loses, and Naruhaya is eliminated from the Blue Lock project.

His relationship with Yoichi Isagi is the most significant in his development. He sees Isagi as a kindred spirit, another ordinary player striving to compete with geniuses. He is honest with Isagi about their shared limitations, creating a bond of mutual respect and rivalry. During their decisive 2v2 match, Naruhaya tries to adapt by imitating Isagi's direct shot technique, but he fails. Conversely, Isagi successfully analyzes and adapts Naruhaya's own off-the-ball movement to gain the upper hand, leading to Naruhaya's elimination. Far from being bitter, Naruhaya accepts his loss with grace. He feels a sense of relief and satisfaction for having reached the Second Selection, acknowledging that his dream of becoming the world's best striker was perhaps naive. Before leaving, he tearfully thanks Isagi for treating him as a worthy opponent and not showing him pity, and he passionately encourages Isagi to keep winning until the end of his life.

Naruhaya's notable ability is his exceptional skill in off-the-ball movement. He describes this weapon as allowing him to "fly across the pitch." This involves intelligent, well-timed runs into space, exploiting the blind spots of defenders to break defensive formations and create scoring opportunities. At the time of the First Selection, he was more experienced and skilled at this than Isagi. His playstyle is best categorized as a "False Nine," a forward who drops deep or moves wide to disrupt the opposition's defensive structure, creating space for teammates rather than simply acting as a traditional target striker. He began playing soccer at the age of five and cites former English striker Michael Owen as his favorite player. Despite his early exit from the main competition, his technical skill and strategic movement, which Isagi later adopts and refines, prove to be a valuable asset, highlighting his potential had he been able to develop further.