Kitazawa-kun Is in A class is a Manga/Manhwa/Manhua in english language, SUGGESTIVE 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

Masashi Kitazawa, a sophomore in high school, had a trauma. The trauma is that I was fat when I was a child! Kitazawa, who diligently dieted and worked hard in middle school, grew up to be a handsome man and was supposed to lead a peaceful school life, but... In the new semester of high school, handsome men and beautiful girls have gathered in Kitazawa's 2nd grade class A for some reason. What's more, he received a secret invitation from Ayame Yagyu, the most beautiful girl in her grade...!?