Haruka Yano is a supporting character in the narrative of Boku wa Imōto ni Koi o Suru. He is depicted as an affluent upperclassman who attends the same school as the twin protagonists, Yori and Iku Yuki. His wealthy background is a consistent aspect of his portrayal throughout the story.

Personality-wise, Haruka is characterized by his romantic pursuit of Iku Yuki, which positions him as a direct rival to her twin brother Yori, who harbors his own complicated feelings for Iku. This love triangle is a central element of his role, fueling tension and emotionally charged confrontations with Yori. Beyond this romantic rivalry, Haruka also serves to inject comedic moments into the storyline, frequently engaging the Yuki twins in lighthearted or humorous scenarios. Physically, he is an adolescent male with brown, neck-length hair and yellow eyes.

Haruka's primary motivation within the story is his desire to win Iku's affection, which brings him into direct conflict with Yori. Despite knowing about the mutual feelings between the twins, he continues his efforts to pursue Iku, though he is described as never forcing the issue or attempting to separate them by underhanded means. His key relationships are defined by this love triangle: his rivalry with Yori and his unrequited romantic interest in Iku.

In terms of character development, Haruka remains largely static, exhibiting no significant evolution or change throughout the narrative arc. His role is consistent as a rival and a source of comic relief. No notable abilities or unique skills are documented for this character. He also appears in the spin-off manga Boku no Hatsukoi o Kimi ni Sasagu, though specific details about his role in that work are not defined.