Niijima Ibuki leads the unit Photon Maiden and serves as student council president at Yoba Academy. Her family operates a shrine, where she sometimes assists as a miko. An early interest in sports led her to participate in various athletic pursuits during childhood. Discovering a passion for dancing and singing in junior high school prompted her to attend a show production school. This background in movement and performance directly informs her role, guiding the physical fitness and dancing skill development of her group members. She proactively balances energetic mentorship with supportive care for her unit. Her active leadership extends beyond title; she guides her groupmates in musical development and personal growth, notably assisting Saki in exploring new creative directions.

Standing 165 cm tall, her appearance reflects an active lifestyle: grey hair typically styled in a tight ponytail, blue-grey eyes, and light skin. Despite her competence, she displays modesty, downplaying her popularity among younger students and dismissing mentions of her dedicated Yoba Academy fan club. She possesses a substantial appetite, capable of competing in speed eating contests, though she generally avoids such activities due to the effort required to manage the resulting calorie intake. She also manages her school's track and field team. The character has been adapted for franchise collaborations, featuring alternate designs based on series including "The Quintessential Quintuplets," "Date A Live," and "That Time I Got Reincarnated as a Slime." Her surname Niijima combines "new" and "island," while her given name Ibuki incorporates characters meaning "clothes," "dance," and "record," with an alternate reading conveying "breath" or "vigor" reflecting her athletic nature.