Airi Kashii is a sixth-grade student in class 6-C at Keishin Academy, where she serves on her class's bulletin placement committee. She is the center for the school's girls' basketball team, wearing jersey number 7. Standing 168 centimeters tall and born on April 5th, she is the tallest and oldest member of her team, but her height causes her extreme shyness and sensitivity; any mention of it often brings her to tears. Her family includes an overprotective older brother, Banri Kashii, a recognized local amateur basketball player, and both her father and brother are tall and muscular while her mother is voluptuous and above average height. The family operates a gym or sports club. Airi also has aquaphobia, a fear of water stemming from a childhood incident where she fell into a lake. Her height complex initially hindered her basketball performance, but through training with Aoi Ogiyama, she learned to use her physical advantages for rebounding, shot-blocking, and close-range scoring. She evolved into a face-up center, becoming a key part of the team's "One Center, Four Shooter" offensive strategy by drawing defenders and creating open shots for teammates. Despite her imposing build, she remains reserved, gentle, and easily unsettled, though she deeply values her friendships. She develops romantic feelings for her coach, Subaru Hasegawa, and accidental comments from him often complicate her emotions. Her official height was never recorded in school due to a missed physical examination while recovering from a cold. She is sometimes called "Prismatic Bud" by the school nurse, a nickname that reflects her shy nature and potential.