Danjo no Yuujou wa Seiritsu suru? (Iya, Shinai!!)

(Chapters 1-44) Himari Inuzuka, a cheerful girl who's never been in love, and Yuu Natsume, a flower-loving boy, became friends by chance. Two years later, the two are still best friends. But when Yuu is reunited with his former crush, the relationship between Himari and Yuu began to change......? (Source: Dengeki Daioh, translated)