Airi Kashii is a sixth-grade student in class 6-C at Keishin Academy, serving as her class's bulletin placement. She is a key member of the school's girls' basketball team, playing as center while wearing jersey number 7. Airi possesses a notably tall and well-developed physique for her age, standing approximately 168 centimeters (5'6")—a height surpassing even some high school students. This stature contributes to a significant personal complex regarding her height, often causing emotional distress when mentioned. Despite her imposing build, she maintains a shy, reserved, and sensitive demeanor. She also lives with aquaphobia, an irrational fear of water stemming from a childhood incident where she fell into a lake. Her family includes an overprotective older brother, Banri Kashii, a recognized local amateur basketball player. The family operates a gym or sports club, and her parents share similarly tall and robust physical traits. Her given name, Airi, combines "love, affection" with "white jasmine," while her surname, Kashii, signifies "fragrance, fragrant" and "oak, mallet." Initially, her height complex hindered her basketball performance, but through training—particularly with Aoi Ogiyama—she learned to leverage her physical advantages. She grew adept at rebounds, shot-blocking, and scoring near the basket. Her playing style evolved into that of a face-up center, using her size to draw defensive attention and create opportunities for teammates, a crucial element in the team's "One Center, Four Shooter" offensive strategy. This development helped her overcome much of her sensitivity about her height and even encourage others with similar traits. She develops romantic feelings for her coach, Subaru Hasegawa, and his accidental comments often complicate her emotions due to her timid nature. Among her peers, she is the oldest, having been born on April 5, and is sometimes referred to by the nickname "Airin" or "Prismatic Bud"—a name given by school nurse Touko Hatano that references her shy nature and potential. Her official height was never recorded in-school due to a missed physical examination while recovering from a cold, though visual comparisons suggest she is comparable in height to or slightly taller than Subaru Hasegawa.