ok kakashi got the MS because obito asked rin to implant his left eye in to kakashies because his was sliced by a rock ninja and it was his birthday present to kakashi so from then on he had a sharingan as his left eye instead of his normal left eye and he has been training his sharingan from the point when he got the sharingan untill he got the MS. and thats how i think kakashi got the MS as for rin thay never really said she was daid for sure but it seems kakashi thinks shes dead and thats all we knowIt will be revealed in Kakashi Gaiden part 2. I reckon it will also reveal how he got his MS.
:| it was a gift for making Jounin.ok kakashi got the MS because obito asked rin to implant his left eye in to kakashies because his was sliced by a rock ninja and it was his birthday present to kakashi so from then on he had a sharingan as his left eye instead of his normal left eye and he has been training his sharingan from the point when he got the sharingan untill he got the MS. and thats how i think kakashi got the MS as for rin thay never really said she was daid for sure but it seems kakashi thinks shes dead and thats all we know