Today Nintendo announced that Splatoon 3 would be released in 2022. In this video, we learn that the world has fallen to a sorry state. The top of the Eiffel Tower is embedded upside-down in a wasteland, and cities look as though they've been sacked by neo-Visigoths. Just the kind of uplifting backstory we need in these times!
BTW: In 2018 I was in Tokyo and went to a Splatoon 2 art show at Tower Records and took photos.