I read this chapter not long ago but I can't seem to find t anywhere. It was a shounen-ai and probably from a yaoi manga..
Story:
Guy A is a very cheerful lad and loves to make friends. Guy B on the other hand is vey quiet and doesn't show much expressions. Guy A starts to befriend him and guy B slowly starts to open up. (There was this metaphor used from guy A's POV that Guy b had his door closed and he was stating to open it)
It's vague from here on but some sort of misunderstanding takes place between Guy A and guy B...guy B kinda gets emotional and runs to the school roof top in the middle of the class. Guy A is worried that he has screwed up everything after guy B was finally opening up to him so he runs after him to the roof and gives some explanation and suddenly kisses him. Guy B gets so shocked that he punches him but later sees that he's bleeding and he gets worried. They clear up the misunderstanding and at the end..the same metaphor was used from guy A's perspective that he's glad that guy B has given him another chance and opened up his sort again..and that he'll never screw up again.

Thank you.

I believe it's Kawaisa Amatte Nanika ga Hyakubai chap 4?

Yes that's it! Thank you so much. 😀