Thank you for the feed back!!
every keys are obtainable, i guarantee it!
if you need some hints:
-2nd key around attic
-3rd key around dining room
-4th key is somewhere in the laundry room
-5th key is somewhere in one of the bedrooms
-6th key is somewhere in the restroom
-attic key is somewhere in the basement's room
the story is self-explainable, you have to finish the game to know what exactly happened to the main character