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 T key here.
Omori Location Key U
You can find the Omori U Key inside Humprey in the water currents by going left twice. Do not forget to solve the bridges puzzle.
Looking for Key V. Find the Omori Key V.
You can find all Omori key locations here.