I don't remember the name of this yaoi manga... But story goes like this on their graduation day a boy confesses his love to his best friend... And I think his friend laughs or something and boy gets rejected...I forgot what happened next... Thanks in advance
I just read this manga and remembered that I've read another manga with the same plot like boy turned into a girl curse... http://www.mangago.zone/read-manga/nyotaika_shita_boku_wo_kishi_sama_tachi_ga_nerattemasu/