Kimi Towa Gokai Kara HajimarimashitagaIt Started From a Misunderstanding; It Started From a Misunderstanding With You But; Kimi to wa Gokai kara Hajimarimashita ga; キミとは誤解からはじまりましたが
From Good Girls Scan BL:
Miike writes a love letter intended for the girl he sees everyday on his way to school. The girl misunderstands and winds up giving the letter to her brother and now Miike and him are dating! How will Miike fix this misunderstanding...?!