This took 9 Months
On my New Game+ run of Sekiro, it took me over 9 months to beat the final boss, Isshin. Of course, this was on and off play, so it didn't actually add up to 9 months of play time.
On my New Game+ run of Sekiro, it took me over 9 months to beat the final boss, Isshin. Of course, this was on and off play, so it didn't actually add up to 9 months of play time.