Kei Tsukishima, a first-year Karasuno High student, towers at 190.1 cm with a lean frame, short blond hair, and golden-brown eyes accentuated by black rectangular glasses. He switches to sports glasses during matches—gifted by his older brother Akiteru—while white headphones and crescent moon-patterned clothing reference his surname’s "moon island" meaning. His detached approach to volleyball originates from childhood disillusionment after uncovering Akiteru’s fabricated claims of being Karasuno’s ace. This betrayal forged Tsukishima’s defensive sarcasm and reluctance to invest fully in the sport. He maintains a complex bond with Tadashi Yamaguchi, whom he shielded from bullies in elementary school yet dismissively labeled the act as "pathetic." A master of calculated provocation, Tsukishima needles passionate teammates like Hinata and Kageyama while cloaking insecurities behind analytical precision. His self-deprecating dismissal of achievements—such as downplaying a match-winning block against Ushijima—masks growing dedication. Training camp mentorship from Kuroo and Bokuto shifts his blocking strategy from reactive to tactical, employing read blocks that exploit opponents’ patterns. The Shiratorizawa showdown crystallizes his evolution: a decisive block against Ushijima sparks visceral thrill, followed by defiantly playing through a hand injury. Post-graduation, he balances volleyball with the Sendai Frogs and a museum career, maintaining cerebral interests like dinosaur figurines and strawberry shortcake. Though mocking Hinata and Kageyama’s academic failures in the "VS Failing Grades" OVA, his barbed challenges covertly spur their efforts. Relationships deepen through guarded loyalty to Yamaguchi, rivalry-driven teamwork, and reconciliation with Akiteru, whose gift of sports glasses and candid reflections on perseverance anchor Tsukishima’s hard-earned commitment to the court.