A yaoi manga were the seme saw a guy hold uke's butt in the train before they bacame lover...

A yaoi manga were the seme saw a guy hold uke's butt in the train before they bacame lovers, and he get angry, and also there was the seme's friend in the train. After that the seme saw the uke again and know that he is his classmate, after that the uke was eating in the brake time in the library and he saw the female teacher hugging the seme. And so on they bacame lovers.

Notes: The manga is yaoi, and school life (high school)
The uke has dark blue hair (i think), wearing glasses, looking always down, setting alone, and have nice butt.
The seme has red hair, handsome, and popular with girls.
The seme's friend has purple hair, and wear something on his head.

________Hope anyone could help, sorry about the bad english, and thanks!___________