Movie
Description
Kasumi Haruno is a fifth-grade student at Takatomi Elementary School and the school idol. Her intense admiration for Drive Head Sonic Interceptor stems from being rescued by it during an out-of-control monorail incident. This fuels her quest to discover the identity of its driver, whom she imagines as tall and handsome—a stark contrast to her classmate Gou Kurumada's actual demeanor. She frequently ridicules Gou for his apparent bathroom breaks, unaware they mask his participation in Drive Head operations. Kasumi blends daydreaming tendencies with brutal honesty and maintains friendships with classmates Mikoto Ishino, Azusa, and Nozomi.

Her character develops through multiple encounters with Drive Head. On a class trip to the Great Ama no Ukihashi suspension bridge, she calms a young boy separated from his mother by giving him her limited-edition Sonic Interceptor phone strap, trusting Drive Head to save everyone. At a disaster prevention event, she briefly mistakes Taiga Yagura for Sonic Interceptor's driver after spotting him inside the machine, though this is disproven later. While participating in a game show audition, Kasumi becomes trapped on a train hijacked by an Evil AI. She receives phone guidance from Gou (using a voice changer), directing her to assist other passengers, deepening her connection to the driver while remaining unaware of Gou's identity.

Kasumi's suspicions about Gou intensify after feverishly following him through a malfunctioning chute into the Mobile Rescue Police headquarters. She encounters the organization's dog, Axel, before fainting and being returned to school, told it was a dream. Later, after spotting Gou walking Axel near the base, she confronts him about the truth, but he evades answering due to secrecy. She also observes a correlation between Gou's bathroom breaks and Drive Head launches, yet dismisses classmates' suggestions he could be a driver, insisting the heroic pilot must be unlike Gou.

In the movie, Kasumi confronts Gou about his changed behavior before admitting her own waning interest in Cyclone Interceptor. While riding a bus, she becomes trapped when Terra's energy field sucks in the vehicle. Her distress call reaches headquarters, leading to her rescue by Cyclone Interceptor. This renews her fandom, though she continues to deny Gou's involvement despite acknowledging his bathroom breaks always coincide with Drive Head deployments. Her curiosity about the driver's identity remains a lingering question in her interactions.