Natsu, Kimi ga Saku (Yaoi)

The following content is intended for mature audiences and may contain sexual themes, gore, violence and/or strong language. Discretion is advised.

From Storm in Heaven:

Shinobu grew up in a town so small that he didn't even have any classmates in elementary school. Without any friends his age, he spent his time learning about flowers with a local horticulture expert. Now that he's moved away to a city, he still sticks to himself, since he never really learned how to make friends. That is, with the exception of Yukihito, who came up to him one day and became his friend. The trouble is, now Yukihito means the world to Shinobu, and he doesn't know what to do about it.