Wataru Komatsuzaki is the younger brother of Lan Komatsuzaki and a first-year student at Seiryō Academy. He deeply admires Shūichi Torigai (Bird), seeing him as a role model. A severe accident during an F-1 race, where debris caused Wataru critical injuries, led Lan to provide him with a life-saving blood transfusion. Wataru carries a lingering sense of responsibility for Lan's subsequent injuries and struggles. He believes this transfusion may have influenced or activated Lan's latent esper abilities, contributing to her difficulties. This belief cemented his protective stance toward her.

Wataru consistently involves himself in Lan's challenges, demonstrating his commitment to assist her. He proactively joined Bird in pursuing a vehicle after Jin Kiryū was abducted by individuals posing as police officers. Even during his own hospitalization following the racing incident, Wataru teased Lan lightheartedly about her relationship with Bird, revealing a playful facet of their sibling bond.