Seiri Fukiyose attends the same Academy City class as Kamijou Touma. Though Aogami Pierce is the official class representative, she frequently assumes the role. Her best friend is Himegami Aisa, and she often interacts with the Delta Force group, representing ordinary school life against Touma's extraordinary adventures. She possesses a slender yet solid build, described as tall for her mid-teens age. She is notably well-endowed and has a prominent forehead, emphasized by her hairstyles and earning her the nickname "Forehead deluxe." Her overall appearance conveys a studious and considerate impression. Fukiyose strongly dislikes people blaming failures on bad luck, particularly targeting Touma for this attitude. While her feelings towards him are debatable, hints suggest possible romantic interest beneath her stern exterior. Characterized as "pretty but lacking sex appeal," she earned the nickname "The iron wall girl." A significant trait is her obsession with health products, frequently ordering them from television shopping channels—a habit known only to Touma—though she loses interest after brief use. She prefers short-term roles during events like the Daihaseisai or Ichihanaransai over long-term positions like class representative, believing the latter offers little growth. During the Daihasei Festival, she nearly died from Oriana Thomson's flash-drying spell, saved when Touma negated it with his right hand, and later recovered medically. In the Academy City Invasion, she violently reacted to Touma's poorly worded request about her breasts, knocking out him and his friends. During the Skill-Out Uprising, she discussed rising food prices with Touma and organized a class vote for a group outing, later showing irritation at his behavior during the meal. In the Document of Constantine Arc, she worked with Touma on school grounds cleanup after others abandoned the task. A moment of accidental indecency occurred during a fork ball game, causing her to adjust her stance. She participated in a lunch retrieval mission during the Acqua of the Back Arc, fleeing school staff. For Ichihanaransai preparations in the British Royal Family Arc, she expressed excitement but headbutted Touma after his comment about preferring waitresses over maids. In the Homecoming Arc, she confronted Touma upon his return to Academy City, angered by his absence during festival preparations and noting his alcohol smell. During the Ichihanaran Festival Arc, she forcibly dragged him back to school after finding him at a station, ignoring his desire to return to his dorm. She tasked him with buying food and later expressed frustration over his disappearance and reported arrest. Her most tragic moment occurs in the Magic God Othinus Arc's alternate world, where Othinus reshapes reality to brand Touma as humanity's enemy. After a coalition attack destroys Shibuya Station's refugee shelter, an injured Seiri is found in the rubble by Touma. As he tends to her, she stabs him with a glass shard, twisting it to maximize damage, believing him to be the world's enemy, leaving Touma severely wounded and emotionally devastated.