Kimi ga Mabushii Sei de

Extremely shy, Koharu Uzuki spent her middle school days alone, unable to make friends. Dreaming of youth, she was determined to make it to high school, but she made a huge mistake when she introduced herself. However, when Aoi Yuuki, the most outgoing boy in her class, spoke to her, things started to change for Koharu's high school life, which had started off with such a blunder...

Koharu Uzuki, a shy girl; Aoi Yuuki, the most outgoing person in her class; Ukino Sora, a childhood friend who goes at his own pace; and Shiratori Miu, a beautiful, solitary girl. A story of love and friendship between four people with different personalities and social classes!

(Source: Comic Walker, translated)