Obtainable at the start of the game.
After the start of the story, in the dojo which can be found behind the house by going left after exiting your home you will enter where sensei was killed. Fuku-san should be training. Above the door he is facing you will see a sign with some writing on it. Use LT to zoom in and then press
to trigger a short cutscene. After it plays out the achievement will unlock.
Edit thanks to JKSullivan:
You do need to do this before you move/look behind the two scrolls hanging on the wall opposite to the door.
Edit according to multiple people:
A few are saying they got it too pop by looking behind the scrolls first. I’m leaving both edits in just in case players need or want to try both methods.