How would you implement the haiku mechanic from Ghost of Tsushima in a 1st person exploration game?

An example of how it works: https://m.youtube.com/watch?v=K9LrO-LSE2Q&pp=ygUXdHN1c2hpbWEgaGFpa3UgbWVjaGFuaWM%3D

How would you implement this in a 3D unity project?