Osoraku Kanojo wa Ore no Aniki wo Neratteru

A high school student has lost faith in girls after repeated experiences where they sought only to get close to his attractive older brother. Determined to avoid such situations, he resolves to trust no one. However, a classmate who is both attractive and persistent begins engaging with him frequently, raising questions about her true intentions. Is she following the same pattern as those before her, or is there another reason behind her interest?