Uke and seme are classmate/friends. The uke is moving away (either due to graduation endin...

Uke and seme are classmate/friends. The uke is moving away (either due to graduation ending or his family moving away, i don't clearly remember). So, this is the last time that the uke is droping by the seme's home. Seme makes tea/coffee and the uke drugs seme's drink. Then the uke has sex with him. The seme doesn't want that kind of forced sex so he asks the uke, why he's doing this. And the uke confesses while doing it with the seme. After doing it the uke gets up and leaves. The seme wants to chase after the uke but he's still drugged so he can't move.
After this point, i just remember the seme stoping the uke OR finding the uke later and accepting his confession. But in between that what happened i don't remember. Another hint, i think the uke had black hair and was wearing a buttoned up gakuren