I can explain it if someone wants

e x p l a i n

As you know I also play Minecraft and I was building the octo expansion I put a YT vid so I could make ab exact copy of the octo expansion including the abandoned shops, and then inside a shop there was a wooden sign with Japanese words, so that means that humans were at least 200 years before splatoon, since wood just lasts on a good state 200 years

But it’s cannon that splatoon takes place more then 10,000 years (or more) after humans went extinct

Humans will only die after the universe dies, it's impossible to kill all humans, if the world would be all like says splatoon with all water, believe me, some humans would survive

What if Mr. Grizz is human!?

My personal theory I made a while ago matches, I won't get into specifics, but my theory is that tartar is the professor, and Mr. Grizz is tartar.

explain please

Ok, sorry couldn't see the notification

well i read ahead and i get it