Haru Sakurai holds the position of student council president during his second year at Holy Cross High School. He orchestrates numerous unusual school-wide events and competitions, often designating fellow student Riku Aoba as a key participant or objective. Despite his responsibilities, Haru actively avoids administrative workloads, notably attempting to delegate Cultural Festival preparations to Riku to lessen his own duties.

His seemingly chaotic actions serve a stated goal: enhancing school life by creating memorable, enjoyable experiences before his third-year academic focus. He strategically engineers these events to foster interpersonal connections, particularly between Riku Aoba and Sayuri Amamiya. For instance, he appoints both to the Cultural Festival organizing committee, forcing collaboration. He later directly assists Sayuri in arranging an uninterrupted confession to Riku under the Legendary Tree, functioning as an unintentional matchmaker.

Frequent collaboration on council matters leads to public perception of a romantic pairing between Haru and Sayuri, causing Riku's misunderstanding. However, their dynamic remains strictly platonic; Sayuri provides essential administrative support preventing council chaos. Beyond council duties, Haru offers Sayuri personal guidance, like advising on Sapporo sightseeing for her date with Riku during a school trip.

Physically, Haru possesses light brown (auburn) hair, blue eyes, and stands 177 cm tall. His birthday is April 1, and his blood type is A. His surname, Sakurai (桜井), combines "cherry blossom" (桜) and "well/pit" (井), while his given name, Haru (晴), means "clear weather."

His influence extends to major school functions beyond the Cultural Festival, including selecting Sayuri as his assistant during a Christmas Eve cosplay party and coordinating the sports festival. These activities consistently reflect his commitment to enlivening the student experience through unconventional methods, even pursuits involving chasing Riku across campus.