For the purpose of this challenge, I define low% as never taking any optional permanent upgrades. This means not using boss memories, prayer beads, skill points, optional prosthetic tools, gourd seeds, optional gourds, and spiritfalls. I did not fight any optional minibosses that grant passive skills, such as O'Rin of the Water. Normal consumables, such as pellets, are allowed. Mortal Draw is allowed, since you must get the Mortal Blade to complete the game.
3:30 Isshin 1
6:40 Isshin 2
15:08 Isshin 3
17:20 Stat screen