A Sharp-Eyed Classmate is a Manga/Manhwa/Manhua in english language, Drama series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

With her fierce eyes and sharp impression, and wary of everyone, 'Ahn Se-young' is a woman to watch out for. Everyone is cautious around her, but a lone boy stands in front of her. "I like you, go out with me!" "......What?!" Se-young is taken aback at the sudden confession of love, but this was just the beginning... The tug-of-war between 'Ahn Se-young', who shows an unexpected side to her as you get closer, and 'Nam Ho-yeol', the straightforward guy who tries to break down her impenetrable facade, begins now!