Trek to Yomi

Throughout the game there are little side areas such as alternate paths or doorways you can go into that contain various items like ammo refills or collectables or, of course, upgrades. Interactable objects have a sparkle to them and the upgrades generally look like a simple item such as a bottle. Interact with one to pick it up and the achievement pops. You should get this in the first chapter with your first stamina or health upgrade. I'm not sure if an ammo upgrade would trigger it but you should have this before those even become available. Just search the side areas, interact with what you find, and you'll get it quickly.

This is 100% guide for all achievements including Ronin and Kensei Run:
(Timestamps are in YouTube pinned comment)