I love this Manhwa so much that its an issue. I've re read it way over 60 times. This is my favourite BL but its also really shit. Its toxic and has some hard issues they come across. In the end it is really sweet. Its not for everyone but give it a go. Its not too long of a series but I absolutely love this manhwa so much.
The plot-
Yubin lives across from his childhood bestfriend Ginu. Yubin has had a crush on Ginu sijnce middle school and doesn't want to let him know. Ginu lives in the other building and can see everything through the windows. One day Yubin jacks off and Ginu sees him and knows hes gay. Then Ginu decides to teach him how to have sex.