Collectors box hidden meaning?

[tituti]

Hello and have a great day to everyone reading this, today my copy of the collectors edition has arrived and i absolutely love this thing, as a warning though i here want to discuss the hidden item included in this box.

When i found the key in the piano i noticed a number, at least in my case 143 , i do not remember there being a specific number in game and was wondering if maybe i had missed something or that there is some other hidden meaning to this key and its number.

I hereby thank Anyone willing to explain and or look for an extra hidden meaning.

[Mr. Merchant]

there's a whole page on omori wiki about that number just search it up