In the Omori game you can obtain a number of keys. These keyboard keys are labeled with a capital letter. The letter keys start with A all the way to Z. You can find the H key here.
Omori Location Key I
You can find the Omori I Key in the dungeons near the skeleton.
Only Omori can collect the I Key. In case Kel, Hero or Aubrey are leading the party the I letter key will be semi-transparent. A semi-transparent key can not be collected.
Looking for Key J. Find the Omori Key J.
You can find all Omori key locations here.