Manabu Kobayashi is a freshman at Kirameki High School who appears outwardly ordinary and friendly. He possesses a pronounced preoccupation with forming connections with female classmates, primarily pursuing this interest through the use of a video camera. Approaching attractive female students under the pretext of conducting student council interviews, he often focuses his camera on areas like their upper body or legs rather than their answers. His fabricated excuses for filming frequently prove unconvincing, sometimes involving mismatched uniforms or suspicious questions, leading to the frequent discovery of his true motives and resulting confrontations.

Despite this socially problematic behavior, Kobayashi consistently earns top grades in exams, demonstrating high intelligence and studiousness. He stands as one of the protagonist's closest friends alongside Tadashi Nanakawa. He often associates with Kai Ryuukouji. Kobayashi proves significantly loyal to the protagonist, readily participating in schemes supporting the protagonist's romantic pursuits, such as disguising himself as Yuu Satsuki to act as bait during Miyako Ookura's route.

Physically, he has black hair, orange eyes, and stands 167 cm tall. His birthday is October 30, making him a Scorpio, and he has blood type A. His personal hobby involves playing dating simulation games.