Responses

are you referring to Isekai Bishoujo juniku ojisan to - Life with an Ordinary Guy Who Reincarnated into a Total Fantasy Knockout ( https://mto.to/series/139784/life-with-an-ordinary-guy-who-reincarnated-into-a-total-fantasy-knockout-official) I don't know if its on mangago but this sounds similiar to what you are looking for
there two male mcs then a goddess of beauty(i think) reincarnated them in some fantasy world but one guy turns into a girl and the other one becomes the hero ion remember much since i read it like almost a year ago